US3394692A

US3394692A - Cutting and assembly of precious stones

Info

Publication number: US3394692A
Application number: US418756A
Authority: US
Inventors: Sirakian Jean
Original assignee: C SIRAKIAN AND FILS
Current assignee: C SIRAKIAN AND FILS
Priority date: 1964-01-31
Filing date: 1964-12-16
Publication date: 1968-07-30
Anticipated expiration: 1985-07-30
Also published as: BE644327A; FR1391988A; GB1005060A

Description

July 30, 1968 J- SIRAKIAN 3,394,692

CUTTING AND ASSEMBLY OF PRECIOUS STONES Filed Dec. 16, 1964 3 Sheets-Sheet 1 INVENTO/i. JEAN S/RAKIAN Affarneys July 30, 1968 v J. SIRAKIAN 3,394,692

CUTTING AND ASSEMBLY OF PRECIOUS STONES Filed Dec. 16, 1964 3 Sheets-Sheet 2 INVENTOR. JEAN SIRAK/AN A! forneys July 30, 1968 J. SIRAKIAN 3,394,692

' CUTTING AND ASSEMBLY OF PRECIOUS STONES Filed Dec. 16, 1964 5 Sheets-Sheet 3 //v VEN ran. JEAN .ISIRA KIA/V r (Li M W A I Iarneys CUTTING AND ASSEMBLY OF PRECIOUS STONES Jean Sirakian, Paris, France, assignor to C. Sirakian & Fils, Paris, France, a corporation of France Filed Dec. 16, 1964, Ser. No. 418,756 Claims priority, application France, Jan. 31, 1964, 962,230; May 21, 1964, 975,268

9 Claims. (Cl. 12530) ABSTRACT OF THE DISCLOSURE A method of cutting and assembling two stones into a marquise or navette wherein the base bezels and base pavilions of the stones are more inclined with respect to the horizontal than conventional cuts including performing the primary faceting,.including the cutting of a base bezel and base pavilion on each stone, performing the finishing faceting without additional faceting of the base bezels and base pavilions and assembling the stones with the base bezels and base pavilions of the two stones in confronting relation. Optimal light reflection is obtained.

Precious stones such as diamonds have great commercial and aesthetic value depending on their color, clarity, cut and size among other factors. The natural beauty and value of the stone are enhanced by the cutting and setting of the stone. One technique for enhancing the value of precious stones is the cutting and joining together of two smaller stones to give the appearance of one larger stone. This technique is important because two small stones generally cost less than one large one and there is less loss in the cutting process. This technique has been attempted by the inventor for producing a so-called Marquise or Navette stone. However, prior attempts have not been entirely successful in that the assembled stones display a dark band or zone in the region of the juncture of the two stones which impairs their brilliance. Moreover, the joint remains visible and dust particles become wedged between the stones. These disadvantages detract from the value and beauty of the assembled stones and prior attempts to eliminate these undesirable qualities have not been successful. One reason for this lack of success is that the marquise-halves or escutcheons are generally elliptical stones and the same basic cutting methods have been applied to them as has been used for the brilliant cutting of generally circular stones. This resulted in dark zones in the assembled stones because optimal light reflection could not be obtained.

The present invention employs a new method of cutting the two halves of the marquise to improve light reflec tion, thereby enhancing the brilliance of the stone and overcoming the aforementioned difiiculties. The number and inclination of facets differ substantially from the conventionally cut marquise-half with the result that the joined stones do not'display a dark zone and dust or powder marks from the'stone cuttings are less in evidence'. The principal features of the method are that the base bezels and base pavilions of the stones are not faceted and they are more inclined with respect to the horizontal than the conventional cuts, and the base bezel has a smaller width than normal. The angles of the facets -United States Patent in relation to each other produce optimal light reflection. An object of the invention is to provide a new method for the cutting of precious stones.

Another object is to provide a new method for cutting the two halves of a marquise stone.

Another object is to provide an improved method of preparing two stones for assembly into a marquise or navette.

These and other objects will be apparent to those skilled in the art and more fully understood by reference to the following description, wherein:

FIG. 1 is a top plan view of the two assembled halves of a marquise stone;

FIlgIGl. 2 is an exploded side elevation of the stones of FIG. 3 is a bottom view of FIG. 1;

FIG. 4 is similar to FIG. 2 showing a variation of the lnvention;

FIGS. 5 and 6 are schematics of side and end views, respectively, of one of the stones of FIG. 1 showing the the inclinations of the various facets;

FIGS. 7 and 8 are schematics of the table and cullett sides, respectively, of a marquise-half illustrating the primary faceting according to the invention;

FIGS. 9, 10 and 11 are top, side and bottom views, respectively, of a variation of the invention.

Referring first to FIGS. 1, 2 and 3 a first embodiment of the invention is shown wherein the two halves of the assembled stones are identical. The assembled marquise is indicated generally as 10 and comprises two like halves 11 which are known as marquise halves or escutcheons. Each stone has a base bezel 12 along which the stones are joined to form a juncture 13. This juncture is shown here principally for illustration since the actual line would barely be visible to the naked eye, one of the advantages of the present invention.

Referring now also to FIGS. 5, 6, 7 and 8 the cutting of the stone will be described. The cutting and faceting will be described first on the top or table side of the stone, then on the bottom or cullett side. The primary faceting of the table side is shown in FIG. 7 and comprises seven primary facets, the base bezel 12, the table 14, two lateral bezels 15 adjacent the base bezel, apex bezel 16, and two lateral bezels 17 adjacent the apex bezel. The inclination of the base bezel 12 is 40 as shown in FIG. 5, and that of the other bezels is 38 as shown in FIGS. 5 and 6. In conventional cuts, the slope of the bezels is 33 or 34. The width of base bezel 12 is also narrower than the width of the other five bezels. The lateral bezels 15 are smaller than those of a conventional cut and the lateral bezels 17 are longer than their corresponding conventional bezels. The finishing faceting is more or less conventional, however the base bezel 12 receives no other faceting. In the finishing, corner facets 1 8, and star facets 19 are cut to complete the table side of the stone as shown in FIG. 1, resulting in twenty-three facets on the table side.

The primary faceting on the bottom or cullett side is shown in FIGS. 5, 6 and 8 and comprises cutting six facets, the base pavilion 20, lateral pavilion 21 adjacent the base pavilion, the apex pavilion 22 and lateral pavilions 23 adjacent the apex pavilion. Optionally, there may be a facet at the cullett apex 24. As seen in FIG. 5 the base pavilion is inclined at an angle of 76, while the lateral pavilions are inclined at an angle of 41. The slope of the apex pavilion varies in accordance with the size of the stone. The apex pavilion does not join the cullett apex 24 but is spaced therefrom as indicated at 25 in FIGS. 5 and 8. Additionally, the cullett apex 24 is positioned at about nine-tenths (W the length of the stone as compared with about six-tenths 7 for a conventional cut. The faceting on the cullett side is completed by cutting the corner facets 26 (FIG. 3) on the lateral and apex pavilions, the base pavilion receiving no faceting. The girdle 27 is left smooth or rounded in the primary faceting but may be finished with a plurality of facets (not shown). The cullett side thus has fifteen or sixteen facets (the facet on the cullett apex being optional). The two identical stones are then assembled as shown in FIG. 2 by mounting the stones in a manner well known in the art so that the two stones are contiguous andthe base bezels and base pavilions of the two stones are in confronting relation.

Referring now to FIG. 4 a variation of the invention is shown comprising two non-identical stones. When assembled, the stones present the same plan view (FIG. 1) as the first embodiment already described. The two stones of FIG. 4 are faceted in essentially the same manner as previously described with certain exceptions as will now be described. The left-hand stone of FIG. 4, has a base pavilion a which extends above the girdle 27 and consequently the base bezel 12a is of lesser height than the base bezel 12 of the first embodiment. Preferably, the base pavilion 20a is extended so that the base bezel 12a is one-half the height it would be if it extended to the girdle as in the first method. The right hand stone of FIG. 4 has a base bezel 12b which extends to the lower edge of the girdle 27. The apex pavilions 22a and 22b are extended up to the top edge of the girdle so that the two stones have sharp edges at these points. The slope of the base pavilions 20a and 2011 may vary between 50 and 60 as compared with 76 in the first embodiment described, and the base pavilions join their corresponding cullett apex at 24. The cullett apex 24 is located at about six-tenths 7 the length of the stone as measured along the longitudinal axis from the apex pavilion to the base pavilion. The number of facets on each stone is the same as in the first embodiment, i.e., twenty-three on the table side and fifteen or sixteen on the cullett side. The stones are assembled as shown in FIG. 4 with the upper part of base pavilion 20a abutting the lower part of base bezel 12b.

Referring to FIGS. 9, l0 and 11, another embodiment of the invention is shown wherein each stone is cut in essentially the same manner as the first embodiment but with a greater number of facets and with other variations now described. The stones in this embodiment are similar to stones which are known technically as shields.

The primary faceting is exactly the same as for the first embodiment except that the apex pavilion joins the cullett apex at 24 (FIG. 11). The final faceting is done in a conventional manner to provide thirty-one facets on the table side and twenty-one or twenty-two facets on the cullett side, as compared with a conventional shield which has thirty-one facets on the table side and twenty-two or twenty-three facets on the cullett side. The marquise-half of this embodiment also differs from the conventional shield in that it has only one smooth face for the base bezel and one smooth face for the base pavilion. The two marquise-halves are joined in the same manner as shown in FIGS. 1, 2 and 3.

When out and assembled according to my invention, the assembled stones exhibit improved light reflecting qualities which enhance their brilliance by eliminating the dark zone of previous assemblies cut in a conventional manner and by rendering the juncture between the two stones practically invisible to the naked eye. The total effect is to give the two stones the appearance of a monolithic marquise or navette.

As will be appreciated by those skilled in the art, it is extremely difficult if not impossible to cut a stone with the exact precision specified herein. Consequently, I intend that wherever an angle is specified, both in the description and in the claims, that it be read to include variations on the order of plus or minus two degrees.

While several embodiments of the invention have been described it will be apparent to those skilled in the art that other variations and modifications are possible within the scope and spirit of the invention.

I claim:

1. The method of preparing two precious stones for assembly into a marquise or navette, comprising,

(a) performing the primary faceting, including the cutting of a base bezel and base pavilion on each stone, and

(b) performing the finishing faceting without additional faceting of the base bezels and base pavilions of the stones.

2. The method as defined in claim 1 wherein the two precious stones so prepared are assembled with the two stones contiguous and with the base bezels and base pavilions of the two stones in confronting relation.

3. The method as defined in claim 2 including the step of placing the upper portion of the base pavilion of one stone into abutting relation with the lower portion of the base bezel of the other stone.

4. The method as defined in claim 1, wherein the primary faceting of each stone comprises,

(a) cutting on the table side,

(1) a table,

(2) a base bezel having a slope of 40,

(3) two lateral bezels adjacent the base bezel having a slope of 38,

(4) an apex bezel, and

(5) two lateral bezels adjacent the apex bezel having a slope of 38, and

(b) cutting on the cullett side,

(1) a base pavilion,

(2) two lateral pavilions adjacent the base pavilion having a slope of 41,

(3) an apex pavilion, and

(4) two lateral pavilions adjacent the apex pavilion having a slope of 41.

5. The method as defined in claim 4, wherein the cutting is performed such that the base pavilions have a slope of 76 and the cullett apex of each stone is located at approximately nine-tenths the length of the stone from apex pavilion to base pavilion.

6. The method as defined in claim 5 wherein the cutting is performed such that the apex pavilion is spaced from the cullett apex and the total facets on each finished stone, exclusive of the girdle and the cullett apex, is twenty-three facets on the table side and fifteen facets on the cullett side.

7. The method as defined in claim 5 wherein the cutting is performed such that the apex pavilion extends to the cullett apex and the total facets on each finished stone, exclusive of the girdle and the cullett apex, is thirty-one facets on the table side and twenty-two facets on the cullett side.

8. The method as defined in claim 4 wherein the cutting is performed such that each stone has a base pavilion with a slope of 50 to 60, the apex pavilion extends to the cullett apex and extends in the direction of the apex bezel to the top edge of the girdle to form a sharp edge with the apex bezel, the base pavilion of one of the stones extends upwardly beyond the girdle, and the base bezel of the other stone extends downwardly to the lower edge of the girdle such that when the two stones are assembled the upper part of the base pavilion of the one stone abuts the lower part of the base bezel of the other stone.

9. The method as defined in claim 8 wherein the cutting is performed such that each finished stone exclusive 5 of the girdle and cullett apex has a total of twenty-three facets on the table side and fifteen facets on the cullett side.

References Cited 2,907,187 10/1959 K-avp 6328 6 FOREIGN PATENTS 4/ 1956 France.

OTHER REFERENCES Grodzinski, Paul, Diamond Technology, 1953, pp.