WO2003053632A2

WO2003053632A2 - System and method for automatic gemstone polishing

Info

Publication number: WO2003053632A2
Application number: PCT/IL2002/001003
Authority: WO
Inventors: Zvi Porat
Original assignee: Dialit Ltd.
Priority date: 2001-12-13
Filing date: 2002-12-12
Publication date: 2003-07-03
Also published as: IL147100A0; WO2003053632A3; IL147100A; WO2003053632A8; AU2002358962A8; AU2002358962A1

Abstract

The invention is of a polishing system and method, which provide a combination of vertical and angular displacement of a gemstone relative to a polishing wheel, the apparatus including a tang, a polishing wheel, a vertical displacement element attached to the tang, and an angular displacement element, attached to the tang. The system of the invention can be readily incorporated into an existing automatic gemstone polishing machine.

Description

SYSTEM AND METHOD FOR AUTOMATIC GEMSTONE POLISHING

FIELD OF THE INVENTION

The present invention is of a polishing system and method, which

preferably provide a combination of vertical and angular displacement to a

polishing wheel. The polishing system and method of the present invention are

preferably used for gemstone polishing. More preferably, the present invention

is a method and system for automatic diamond polishing.

BACKGROUND OF THE INVENTION

Diamonds are utilized in a wide-range of applications due to their

unique physical, optical and chemical properties. The characteristic properties

include the following. Diamond is the hardest known substance. In addition,

diamonds have the highest atomic density and the highest thermal conductivity

at room temperature. Diamonds exhibit low friction and wear properties, are

chemically inert and are wide-band gap semiconductors. The uses of diamonds

include, use in cutting tools, use in high power electronic devices, use in low

friction and wear surfaces, components for electronic devices and gemstones

used for jewelry purposes.

Most uses of diamonds require shaping and polishing of the diamond

surface to various degrees , in order to produce smooth surfaces of the

diamond, depending on the desired application. Diamonds are commonly

polished by a specialized instrument, known in the art as a 'tang' generally polished by a specialized instrument, known in the art as a 'tang' generally

using one of two different methods, manual polishing or automatic polishing.

Automatic polishing is carried out by automatic polishing machines for

polishing facets until the polishing reaches a pre-determined position.

Thereafter, the polishing is stopped automatically and then indexing to the next

facet to be polished, takes place. Contemporaneously, the automatic polishing

machines automatically adjust for the correct grain orientation. The term 'grain'

is defined herein as the angle between the velocity vector of the polishing

wheel and the crystal structure o'f the diamond.

The disadvantages of manual and automatic practices known in the art

include the following. The manual polishing methods of the background art fail

to provide combination of angular and vertical displacement. Diamonds

characteristically include different angled surfaces. Therefore, when polishing a

diamond, which by necessity has to be polished in different angles, the polisher

has to change the level of the tang, every time the polishing angle is changed.

Furthermore, when the diamond size is changed the manual polishing method

does not compensate for this and the polisher must re-level the tang.

Extensive re-leveling generally results in low productivity. Conversely,

little or no leveling generally results in decreased quality diamonds.

In automatic polishing, precise vertical displacement is essential for

creating even angles and sizes of the diamond facets. Uneven angles and facets

of diamonds result in significantly depreciated market for the processed diamond, or necessitate additional manual corrections, significantly increasing

production costs.

For the purpose of achieving a high degree of precision, tight tolerances

are required, thereby resulting in a high degree of friction between vertical

displacement elements during the vertical displacement. Thus, the high friction

levels, between vertical displacement elements, produced by the vertical

displacement of the diamond on the polishing wheel, significantly limit the

capability of controlling the diamond during the polishing process as described

hereinbelow.

High degrees of friction, between vertical displacement elements,

significantly limit the capability of controlling the degree of pressure applied by

the diamond on the polishing wheel.

Insufficient pressure of the diamond on the polishing wheel results in

lower polishing rates, thereby resulting in low productivity and higher

production costs. Conversely, excessive pressure generally damages the

diamond being processed.

In addition, due to high friction, between vertical displacement elements,

in the vertical displacement during automatic polishing, detecting of the first

contact point between a diamond and polishing wheel is extremely unreliable.

Hereinafter, the term "Scaife touch detection" refers to any first contact

point between a diamond and a polishing wheel

Hereinafter, the term "stop point" refers to any point at which polishing

of a facet is ceased. The Scaife touch detection reference point is necessary for determining

the distance between the first contact point of the diamond and stop point.

Furthermore, Scaife touch detection is often for controling and as a refernce

point for altering characteristics of processes and displacement of any actuators

or sensors used with the polishing system.

A further disadvantage of the automatic polishing methods and systems

of the background art is due to the fact that a diamond is a non-isotropic

material and polishing can only be performed at a certain grain position.

Namely, at a certain angle between the diamond crystal and the velocity vector

of the polishing wheel. The method commonly used in the art is based on

measuring the degree of vertical displacement occurring during polishing within

a certain time frame for different grain positions, thereby ascertaining where

the highest and accepted value of polish occurs and thereafter polishing where

the highest and accepted value of polish occurs.

Hereinafter, the term "Grain position for best polish" refers to any angle

where the highest and accepted value of polish occurs.

Due to the relative high friction, between vertical displacement

elements, encountered in precise vertical displacement during polishing,

vertical displacement is often disturbed, distorted or not executed.

There is therefore a need for a system and method, such as is disclosed

in the present invention, to provide a solution to the aforementioned problems

and to be more efficient and cost-effective than known automated or manual

polishing devices known in the art. SUMMARY OF THE INVENTION

The present invention provides a stand-alone gemstone polishing system

and method, combining vertical and angular displacement of a diamond

relatively to a polishing wheel. This novel feature results in a method that uses

the vertical high precision displacement to maintain polishing independent of

the size or angle of the gemstone. Preferably, the present invention is a method

and system for automatic diamond polishing.

The present invention also provides a system, which can be incorporated

into an existing automatic polishing machine, which preferably includes the

surrounding elements of the system.

Furthermore, the present invention provides a stand alone semi

automatic apparatus. Moreover, the system of the present invention can be used

as a part of a semi-automatic polishing apparatus, wherein optionally not all

surrounding elements of the system are utilized.

In addition the system of the present invention provides a method of

controlling the applied pressure or weight on the gemstone, which is being

polished.

Still further, the present invention provides a method of precise detection

of the initial contact point between the stone and the polishing wheel. This

precise position is used as a reference point for calculating the distance of the

polishing stop point.. The present invention also provides a method of calculating the

calculating the grain, the optimum grain position and corresponding best rate of

polish position.

In a first embodiment the present invention provides a system

-5

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic side view of a standard manual 'tang' known

in the art;

FIG. 2 shows a schematic, side view of an automatic polishing machine

10 known in the art;

FIG. 3 shows a schematic side view of the system of the present

invention utilized in an automatic polishing apparatus; and

FIG. 4 shows a schematic top view of an alternative embodiment of the

system of the present invention.

15 FIGS. 5a-5c show a schematic top view of sub components of

alternative embodiments of the system of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a stand-alone polishing system and

20 method combining vertical and angular displacement of gemstones relatively to

a polishing wheel. This novel feature of the present invention results in a

method for using a high precision vertical displacement, maintaining optimal

polishing irrespective of size or the angle of the gemstone relatively to the polishing wheel. Furthermore, the system of the present invention includes a

sensing mechanism for sensing angular displacement during polishing, thereby

readily facilitating substantially contemporaneous optimal vertical and angular

displacement of a gemstone during the polishing process.

In the system of the present invention, the relatively high friction

encountered, between vertical displacement elements, in the vertical

displacement has no adverse effect on the grain position, Scaife touch detection

or pressure control due to the system not being a part of the precise sensing

device used for weight/pressure, control, Scaife touch detection or best grain

position.

Hereinafter, the term "Pavilion" or "Bottom" refers to any substantially

lower, or bottom part of a gemstone.

Hereinafter, the term "Crown" or "Top" refers to a substantially upper

portion or top part of a gemstone.

Hereinafter, the term "Table" refers to any substantially flat surface of a

gemstone situated substantially above the crown of a gemstone.

Hereinafter, the term "grain displacement assembly" refers to any

assembly for readily rotateably displacing gemstone substantially

perpendicularly to the surface of a polishing wheel, for the purpose of obtaining

an optimal grain position.

Hereinafter, the term "facet dislpacement assembly" refers to any

assembly for readily rotateably displacing a gemstone along its vertical axis for

purpose of polishing varying facets of a gemstone Hereinafter, the term "stroke displacement assembly" refers to any

assembly for readily displacing a gemstone substantially paralel to the surface

of a polishing wheel substantially contemporanously with increasing or

decreasing the distance between the center of the gemstone and the center of

the polishing wheel.

The present invention further provides a system for controlling vertical

displacement of a gemstone during the polishing process responsively to

detection of angular displacement by an angular displacement sensor.

The present invention further provides a system which can be

incorporated into an existing automatic polishing machine, which preferably

includes the surrounding elements of the system of the present invention such

as, but not limited to grain displacement assembly, facet displacement assembly

and stroke displacement assembly.

Furthermore, the present invention provides a stand-alone semi

automatic apparatus, which optionally can be used as a replacement to manual

hand-held tangs, lifters for providing ready vertical displacement of a gemstone

or sliders for providing ready "stroke" displacement.

Further still, the system of the present invention can be used as a part of

a semi-automatic polishing apparatus, wherein optionally part of the

surrounding elements of the system of the present invention are utilized. By

way of example only, the system can optionally utilize a manual indexing of

facets. In all embodiments, the present invention additionally provides an

option of a second angular displacement responsive to a sensor, thus providing

a method tor readily and rapidly ascertaining a best grain position.

Hereinafter, the term "fancy stone" refers to any refers to any gemstone

devoid of a substantially round or rotationally symmetrical cut cross-section

when viewed from the top.

Hereinafter, the term "Press Pot" or "Pot" refers to any gemstone

securing means for securing a gemstone during a polishing process.

Hereinafter, the term "Wass cover" refers to any device for positioning a

gemstone, such that the first facet to be polished is readily positioned in

relation to the polishing wheel.

The system of the present invention optionally includes a manual

faceting /mode, an automatic faceting mode, or a combination thereof. In

manual faceting mode, the apparatus of the present invention polishes a single

facet at a time, wherein an operator manually rotates the gemstone from the

facet being polished to the next facet to be polished. The manual mode

optionally uses all types of suitable polishing heads (dop's) including, but not

limited to, Top, Bottom, Table, Fancies, Press pot, and Wass cover.

In automatic faceting mode, the system of the present invention

automatically completes polishing the required number of facets, alternating

automatically from polishing one facet to another by means of any suitable

device, which is preferably an electrical device, including, but not limited to, a actuator or solenoid. Upon completion of polishing the requested number of

facets, the system terminates the polishing procedure.

Hereinafter, the term "ring" refers to any termination point indexing

element utlizing an electrical short to signal a termination point, which does not

secure the gemstone.

The system of the present invention provides optional modes of

terminating the facet polishing. These modes of termination include, but are not

limited to, the following. Termination of facet polish by contact of the ring or

pot holding the diamond, with the polishing wheel, whereby thecontact

between the ring or put and the polishing creates an electrical short, thereby

indication that thhe gemstone has reached to the polishing termination point.

By way of example only, the pot holding the diamond is selected such

that upon the pot contacting the polishing wheel an electrical short is created,

thereby providing a cessation signal for terminating the facet polishing.

Alternatively, termination of facet polishing is performed upon

completion of a function to remove material from the gemstone' s surface of a

preset number of microns.

Hereinafter, the term "contact recognition" refers to any contact after an

electrical short occurs between the pot or ring and the polishing wheel,

subsequent to contact between the ring or pot and the polishing wheel.

Termination of facet polishing can also be performed upon completion

of a function for removing material from the gemstone' s surface of a preset

number of microns, after contact recognition. Alternatively, termination is achieved by the first recognition of either

completion of a function to remove a preset amount of microns from the

diamond surface, after contact recognition.

Thus, the following two modes are readily facilitated. First, polishing of

a first facet according to any of the methods hereinabove. Second, measuring

the height of vertical displacement element above the polishing wheel at

substantially the exact time of completing the polishing of the first facet

according to any of the methods described hereinabove. Thereafter, repeating

the process for the remaining facets and polishing according to the same height

measured on the first facet being completed.

The system of the present invention utilizes the substantially frictionless

angular displacement responsive to a sensor, for precisely controlling the

vertical dop shaft, by repeatedy and substantially constantly displacing the

vertical dop shaft up and down substantially vertically, such that the vertical

dop shaft is kept substantially vertical in relation to the polishing wheel.

Alternatively, the system of the present invention utilizes the

substantially frictionless angular displacement responsive to a sensor, for

precisely controlling the vertical holding device, by repeatedy and substantially

constantly displacing the vertical displacment device up and down substantially

vertically, such that the vertical dop shaft is kept substantially vertical in

relation to the polishing wheel.

Furthermore, the system of the present invention uses a substantially

frictionless angular displacement combined with any kind of sensor to precisely detect the Scaife touch point between, the stone on the polishing wheel, as

detailed hereinabove.

The precise position is used as a reference point for calculating the

distance of the polishing stop point from the surface of the gemstone.

Furthermore, the system of the present invention utilizes the

substantially frictionless angular displacement combined with a sensor as a

novel method for readily and rapidly ascertaining the best rate of polish

position.

In addition, the system of the present invention uses the substantially

frictionless angular displacement combined with a sensor to precisely control

the pressure applied by the gemstone on the polishing wheel during the

polishing process.

The present invention additionally provides a method for controlling the

pressure or weight applied by the gemstone on the polishing wheel during the

polishing process.

The system and method of the present invention provide a ready and

efficient method of adding a second angular displacement responsive to a

sensor, resulting in an additional method for readily and rapidly obtain the

Grain position for best polish, based on measuring the friction between the

stone and the polishing wheel, during the polishing process.

The automatic polishing apparatus of the present invention therefore

provides a system that overcomes the outlined disadvantages of manual and

automatic polishing methods available in the art. The principles and operation of systems according to the present

invention may be better understood with reference to the figures. The figures

show a preferred embodiment of the present invention and are not limiting.

Figure 1 shows a schematic side view of a tang 10 commonly used as a

standard manual polishing device known in the art. The manual system is

described in order to clearly show the significant structural, componential and

functional differences between the system of the present invention and the

standard manual polishing device. Manual tang 10 is commonly used for

manual polishing of diamonds. Tang 10 includes a securing dop 12 for securing

a diamond 14. Diamond 14 is secured at a first extremity 16 of tang 10, whilst a

second extremity 18 of tang 10 includes two supporting structures 20, held on a

support base 22. A user commonly displaces tang 10 along an arc, wherein the

axis of displacement is supporting structures 20. Thus, diamond 14 is displaced

along the arc until diamond 14 contacts a polishing wheel 24. Supporting

structures 20 further include two screw elements 26. Preferably, a height 28 of

screw elements 26 is set for the purpose of leveling tang 10, such that a vertical

dop shaft 30 is substantially perpendicular to polishing wheel 24 at substantialy

the exact point of polishing cessation on polishing wheel 24. Each diamond 14

is then optionally polished at different angles, as well as a single diamond 14,

being polished such that different facets are readily polished at different angles.

Figure 2 shows a schematic side view of an automatic polishing machine

as known in the art. This system as shown is commonly used for automatic

polishing of diamonds. A tang 10, includes a securing dop 12 for securing a diamond 14. Tang 10 includes a linear- displaceable element 32 for vertically

displacing tang 10. Preferably, diamonds 14 of varying sizes and having any

angle of facets do not adversely effect the leveled perpendicular dop shaft 30 in

relation to polishing wheel 24.

Figure 3 shows a schematic side view of the system of the present

invention utilized in an automatic polishing apparatus. This system can

optionally be used to polish a gemstone, preferably a diamond. For the purpose

of description of one embodiment of the invention in figure 3, which is in no

way limiting, the gemstone will be referred to as a diamond. The main

components of the system according to the present invention include the

diamond holding system, vertical displcement mehanism, angular displacement

mechanism and sensor system.

As shown in Figure 3, a tang 10 includes a securing dop 12 for securing

a diamond 14 in a substantially fixed position. Tang 10 preferably includes a

displacement mechanism 34 for combined vertical and angular displacement.

Displacement mechanism 34 preferably operates via a linear displaceable

element 36, attached to, or integrally formed with a stationary fixture 37. An

angular displacement axis 38 is preferably attached to, or integrally formed

with linear displaceable element 36. For the purpose of performing angular

displacement, a leveling screw element 40 is provided for leveling tang 10,

such that dop grain shaft 30 is substantially perpendicular to polishing wheel

24. More preferably, leveling screw, element 40 readily facilitates leveling

tang 10, such that dop grain shaft 30 is precisly perpendicular to polishing

wheel 24.

Leveling screw element 40 is optionally controlled by a sensor 42.

Optionally, sensor 42 can be set to any sensitivity level for readily measuring

any desirable parameter including, but not limited to, weight/pressure applied

with diamond 14 on polishing wheel 24, displacement of diamond 14 Scaife

touch point, and a termination point of polishing of a facet of diamond 14 on

» polishing wheel 24. In a preferred embodiment described herein, sensor 42 is a

weight/pressure sensor, for substantially continuously weighing the weight of

tang 10. A vertical displacement actuator 46 is provided for raising and

lowering tang 10 away and towards from polishing wheel 24 repectively, while

preferably maintaining dop grain shaft 30 substantially perpendicular to

polishing wheel 24.

Occasioning on diamond 14 contacting polishing wheel 24 sensor 42

detects a reduction in weight/pressure owing to polishing wheel 24 bearing

some of the weight of diamond 14. Thus, Scaife touch point is precisely

recognized, as it involves only the angular displacement, used to maintain dop

grain shaft 30 substantially perpendicular to polishing wheel 24 and therefore,

the angular displacement is substantially frictionless.

The detection of the Scaife touch point occurs substantially

irrespectively of any weight change detected by sensor 42. Furthermore, the

vertical displacement is irrelevant to the process of determing the Scaife touch point due to the process of detrmining.the Scaife touch point requiring any

weight change detected by sensor 42 combined with the angular displacement.

Thus, and as described hereinabove, the resulting measurement of the

Scaife touch poitn is highly accurate.

Similarly, control of the weight/pressure between diamond 14 and

polishing wheel 24 is readily achieved. As vertical displacement via vertical

displacement actuator 46 continues in a generally downward displacement,

more weight is applied on polishing wheel 24 by diamond 14 and less weight is

applied on sensor 42. The exact weight exerted on diamond 14 can also be

readily calculated by subtracting the current pressure of diamond 14 on sensor

42 from the initial presure applied by diaond 14 on sensor 42.

The descending displacement of vertical actuator 46 is terminated

occasioing on the desired weight/pressure of diamond 14 is obtained. In this

way, highly accurate weight/pressure control on processing diamonds 14 is

readily achieved due to the substantially frictionless anguler displacement.

Subsequently, diamond 14 contacts polishing wheel 24 and applys the

required weight/pressure between diamond 14 and polishiig wheel 24.

Polishing optionally continues by maintaining the applied weight/pressure for

as long as the polishing process continues.

During polishing, diamond 14 brings about a reduction of the weight

applied to polishing wheel 24. Consequently, less weight is carried by wheel 24

and more weight is borne by sensor 42. In order to maintain the same pressure

on polishing wheel 24, vertical actuator 46 displaces tang 10 in a downwards direction for the purpose of maintaining the required weight. This cycle of

events continues until termination of the polishing process, as described

hereinabove.

As iterated hereinabove, the 'grain' is defined as the angle between the

velocity vector of rotating polishing wheel 24 and the crystal structure of

diamond 14. The best grain position is used for the purpose of determining an

optimal rate of polish of diamond 14. Optionally, the system of the present

invention employs two different methods for determining the best grain

position. In one embodiment the ratio between displacement and time is

determined, in different grain positions, by rotating a dop grain shaft actuator

48. The grain position is then selected according to the position in which the

largest ratio between displacement and time occurred. In an alternative

preferable embodiment, readings of weight change on sensor 42 are measured

while in different grain positions, by rotating dop grain shaft actuator 48. The

position in which the greatest weight change is measured, is defined as the best

grain position.

In a further embodiment, the system of the present invention optionally

includes a second angular displacement axis 49. The second angular

displacement axis 49 is the axis more affected by the friction arising from the

contact of diamond 14 with polishing wheel 24 during the polishing process.

The higher the friction, the higher the rate of polish. A screw element 50

is held against pressure sensor 52. When polishing occurs, the friction between

diamond 14 and polishing wheel 24 is high and the pressure of screw 50 on the sensor 52 is decreased. During polishing, grain actuator 48 rotates diamond 14

substantially 360 degrees and the best polishing position is determined by the

grain position in which the pressure on sensor 52 is lowest.

The system of the present invention optionally further includes

surrounding elements including, but not limited to a facet displacement

assembly 54 and a stroke displacement assembly 56.

Preferably, stroke^' displacement assembly 56 readily facilitates leveling

stroke displacement assembly 56 during stroking, responsive to sensor 42

detecting a constant pressure between diamond 14 and polishing wheel 24.

Figure 4 shows a top view of Figure 3. Thus, tang 10 preferably includes

a displacement mechanism 34 for combined vertical and angular displacement.

Displacement mechanism 34 preferably operates via a linear displaceable

element 36, attached to, or integrally formed with a stationary fixture 37. An

angular displacement axis 38 is preferably attached to, or integrally formed

with linear displaceable element 36.

In a further embodiment, the system of the present invention optionally

includes a second angular displacement axis 49. The second angular

displacement axis 49 is the axis more affected by the friction arising from the

contact of diamond 14 with polishing wheel 24 during the polishing process.

The higher the friction, the higher the rate of polish. A screw element 50

is held against pressure sensor 52. When polishing occurs, the friction between

diamond 14 and polishing wheel 24 is high and the pressure of screw 50 on the

sensor 52 is decreased. During polishing, grain actuator 48 rotates diamond 14 substantially 360 degrees and the best polishing position is determined by the

grain position in which the pressure on sensor 52 is lowest.

A bias 58 is provided for biasing screw 50 towards sensor 52.

Preferably, bias 58 can be readily set to any pressure beneficial for enhanced

polishing.

Figures 5a-5c show a preferered retro-fitting of an existing polishing

system as shown in Figure 5 a to an angular displacement system and sensor as

shown in Figure 5b. Thus, an apparatus combining vertical and angular

displacement is obtained by retrofitting an existing polishing system with an

angular displacement system and a sensor as shown in Figure 5c.

While the invention has been described with respect to a limited number

of embodiments, it will be appreciated that many variations, modifications and

other applications of the invention may be made.

Claims

What is claimed is:

1. A gemstone polishing system comprising:

(a) a tang including a securing dop for securing a gemstone;

(b) a polishing wheel;

(c) a vertical displacement element, attached to said tang, for

vertically displacing said tang in relation to said polishing wheel;

and

(d) an angular displacement element, attached to said tang, for

angularly displacing said tang in relation to said polishing wheel.

2. The gemstone polishing system of claim 1, further comprising a

sensor responsive to angular displacement of said tang, for

leveling said tang in relation to said polishing wheel.

3. The gemstone polishing system of claim 1, further comprising a

leveling mechanism responsive to angular displacement of said

tang, for leveling said tang in relation to said polishing wheel.

4. A gemstone polishing system for polishing a surface of a

gemstone, the system comprising:

(a) at least one securing mechanism, said securing mechanism being

configured to secure a gemstone; (b) at least one vertical ^• displacement element for vertical

displacement of said tang in reltion to a polishing wheel; and

(c) at least one angular displacement element for angular

displacement of said tang in relation to said polishing wheel.

5. The gemstone polishing system of claim 4, further comprising a

sensor responsive to angular displacement of said tang, for

leveling said tang in relation to said polishing wheel.

6. The gemstone polishing system of claim 4, further comprising a

leveling mechanism responsive to angular displacement of said

tang, for leveling said tang in relation to said polishing wheel.

7. The gemstone polishing system of claim 4, wherein said system is

automated.

8. The gemstone polishing system of claim 1, wherein said system is

semi-automated.

9. The gemstone polishing system of claim 4, wherein said system is

part of a semi-automated polishing system.

0. The gemstone polishing system of claim 4, wherein said system is

a stand-alone semi-automated system.

11. The gemstone polishing system of claim 5, wherein said sensor is

utilized to measure a Scaife touch point.

12. The gemstone polishing system of claim 5, wherein said sensor is

utilized to control weight and pressure on said gemstone.

13. The gemstone polishing system of claim 5, wherein said sensor is

selected from the group consisting of weight/pressure sensor,

displacement sensor and contact sensor and combinations thereof.

14. The gemstone polishing system of claim 4, wherein said gemstone

is a diamond.

15. The gemstone polishing system of claim 4, wherein said vertical

displacement element further comprises a linear displacement

element.

16. The gemstone polishing system of claim 4, wherein said angular

displacement element further comprises an angular displacement

axis.

17. The gemstone polishing system of claim 16, wherein said angular

displacement axis employs a leveling screw to level said tang.

18. The gemstone polishing system of claim 4, wherein said angular

displacement element further comprises two angular displacement

axis.

19. The gemstone polishing system of claim 4 further comprising a

surrounding element.

20. The gemstone polishing system of claim 19, wherein said

surrounding element is selected from the group consisting of grain

displacement assembly, facet displacement assembly and stroke

displacement assembly.

21. The gemstone polishing system of claim 4, comprising a manual

faceting mechanism.

22. The gemstone polishing system of claim 4, further comprising an

automatic faceting mechanism.

3. A gemstone polishing tang system employing angular and vertical

displacement, mounted on an existing automatic polishing

machine, for polishing a surface of a gemstone, the system

comprising:

(a) at least one holding mechanism, said holding mechanism being

configured to securethe gemstone;

(b) at least one_. vertical displacement system for vertical displacement

of the tang; and

(d) at least one angular displacement system for angular displacement

of the tang.

24. The gemstone polishing tang system of claim 23 further

comprising a sensor.

25. The gemstone polishing tang system of claim 24, wherein said

sensor is utilized to measure a Scaife touch point.

26. The system of claim 24, wherein said sensor is utilized to control

weight and pressure on said gemstone.

27. A method of automatically polishing a gemstone comprising the

steps of: (a) providing a tang system for polishing a gemstone, the

system including:

(i) at least one securing mechanism, said securing

mechanism being configured to secure said

gemstone;

(ii) at least one vertical displacement system for vertical

displacement of said tang,

(iii) at least one angular displacement system for angular

displacement of said tang; and

(iv) a polishing wheel for polishing said gemstone;

(a) providing a gemstone to be polished by said system; and

(b) polishing said gemstone with said provided system.

28. A method of determining a Scaife touch point, comprising the

steps of:

(a) providing a tang system for polishing a gemstone, the system

including:

(i) at least one securing mechanism, said securing mechanism

being configured to secure said gemstone;

(ii) at least one vertical displacement system for vertical

displacement of said tang,

(iii) at least one angular displacement system for angular

displacement of said tang; and (iv) a polishing wheel for polishing said gemstone;

(b) providing a gemstone, said gemstone being secured in said

securing mechanism;

(c) leveling said tang by means of a leveling screw configured to said

angular displacement system;

(d) lowering said tang to said polishing wheel by means of said

vertical displacement system, thus lowering said gemstone

towards said polishing wheel; and

(e) reading a change in said sensor when the gemstone contacts said

polishing wheel to determine said Scaife touch point of said

gemstone.

29. The method of claim 28, wherein said sensor monitors the

pressure between said gemstne and said polishing wheel.

30. The method of claim 28, wherein said gemstone is a diamond.

31. A method of controlling pressure between a gemstone and a

polishing wheel, during a gemstone polishing process, comprising

the steps of:

(a) providing a tang system for polishing a surface of a gemstone, the

system including: (i) at least one securing mechanism, said securing

mechanism being configured to secure said the gemstone;

(ii) at least one vertical displacement system for vertical

displacement of said tang,

(iii) at least one angular displacement system for angular

displacement of the tang; and

(iv) a polishing wheel for polishing said gemstone;

(b) providing a gemstone, said gemstone being secured in said

securing mechanism;

(c) leveling said tang by means of a leveling screw configured to

said angular displacement system;

(d) providing a sensor for reading the pressure between said

gemstone and said polishing wheel;

(e) reading said sensor at time zero to determine initial pressure;

(f) lowering said tang to said polishing wheel by means of said

vertical displacement system to lower said gemstone towards

said polishing wheel;

(g) reading said sensor at any time point to determine current

weight;

(h) calculating weight on said gemstone by subtracting said initial

weight from said current weight; and

(g) terminating said vertical displacement when reaching the desired

pressure between said gemstone and said polishing wheel.

32. A method of polishing a gemstone comprising the steps of:

(a) providing a tang system for polishing a surface of a gemstone, the

system comprising:

(i) at least one holding mechanism, said holding mechanism

being configured to securethe gemstone;

(ii) at least one vertical displacement system for vertical

displacement of the tang,

(iii) at least one angular displacement system for angular

displacement of the tang; and

(iv) a polishing wheel for polishing said gemstone;

(b) providing a gemstone, said gemstone being held in a dop of said

holding mechanism;

(c) leveling said tang by means of a leveling screw configured to said

angular displacement system;

(d) providing a sensor, which reads the weight;

(e) reading said sensor at time zero to determine initial weight

(f) lowering said tang to said polishing wheel by means of said

vertical displacement system to lower said gemstone towards said

polishing wheel;

(g) reading said sensor at any time point to determine current weight;

(h) calculating weight on gemstone by subtracting said initial weight

from said current weight; i) terminating said vertical displacement downwards when reaching

the desired weight to control the pressure between said gemstone

and said polishing wheel;

(j) polishing said gemstone with said polishing wheel resulting in

decreased pressure between said gemstone and said polishing

wheel and more weight on said sensor;

(k) maintaining said weight on said polishing wheel by lowering said

tang; and

(1) repeating steps (h) and (i) until completion of polishing.

33. The method of claim 32 further comprising the step of

terminating said polishing.

34. The method of claim 33, wherein said step of terminating said

polishing is achieved by contact of a gemstone securing element

with said polishing wheel.

35. The method of claim 33, wherein said step of terminating said

polishing is achieved by achieving removal of a preset amount

of material from said gemstone surface.

36. The method of claim 33, wherein said step of terminating said

polishing is achieved by contact of a gemstone securing element with the polishing wheel or achieving removal of a preset

amount of material from said gemstone surface.

37. The method of claim 33-36, wherein said step of terminating

said polishing is achieved by said step of either contacting of a

gemstone holding element with the polishing wheel or achieving

removal of a preset amount from the gemstone surface.

38. The method of claims 33-37 further comprising the steps of

polishing a first facet of said gemstone, according to any of the

methods of claims 33-37, and measuring a height of vertical

displacement element above said polishing wheel, at

substantially the exact time of terminating the polishing of said

first facet according to any of the methods of claims 33-37,

thereafter, repeating the process for said remaining facets and

polishing according to said height measured on said first facet

being completed.

39. A method of determining the optimum grain position of a

gemstone comprising the steps of:

(a) providing a tang system for polishing a surface of a gemstone,

the system comprising: (i) at least one securing mechanism, said securing

mechanism being configured to secure said gemstone;

(ii) at least one vertical displacement system for vertical

displacement of the tang;

(iii) at least one angular displacement system for angular

displacement of the tang;

(iv) a polishing wheel for polishing said gemstone; and

(v) a dop shaft actuator, said dop shaft actuator configured

to rotate 360 degrees and substantialy

comtemporanously read any weight change;

(b) providing a gemstone, said gemstone being secured in a dop of

said securing mechanism;

' (c) leveling said tang by means of a leveling screw configured to

said angular displacement system;

(d) providing a sensor for reading a weight;

(e) reading said weight changes by means of said dop shaft actuator;

and

(f) determining a position when said weight change reading is

maximal, thus defining a best grain position.

40. The method of claim 39, further comprising the step of polishing

said gemstone at said best grain position to achieve a best rate of

polish of the gemstone.

1. The gemstone polishing system according to any one of claims

1-26, substantially as herein described and with reference to the

figures.

42. The method according to any one of claims 27-40, substantially

as herein described and with reference to the figures.

43. The gemstone polishing system according to 41, further

comprising a stroke displacement assembly for facilitating

leveling said stroke displacement assembly during stroking,

responsive to said sensor detecting a constant pressure between

said gemstone and said polishing wheel.