GB2445147A

GB2445147A - Manufacturing a decorative item

Info

Publication number: GB2445147A
Application number: GB0624806A
Authority: GB
Inventors: Christopher William Sellors
Original assignee: C W SELLORS
Current assignee: C W SELLORS
Priority date: 2006-12-13
Filing date: 2006-12-13
Publication date: 2008-07-02
Anticipated expiration: 2026-12-13
Also published as: GB2445147B; GB0624806D0

Abstract

A decorative item such as jewellery is manufactured by adhering a layer of gemstone 12 such as Blue John stone to a layer of mother-of-pearl 14 and performing a thinning operation on at least part of the layer of gemstone. The gemstone may be translucent prior to the thinning operation, or an area of the gemstone is substantiallv non-translucent prior to the thinning operation, the thinning operation being performed to such an extent that at least part of the non-translucent area becomes translucent. The gemstone may be adhered between two layers of mother-of-pearl. The thinning operation may involve contouring or shaping.

Description

A METHOD OF MANUFACTURING A DECORATIVE ITEM

The invention relates to a method of manufactunng a decorative item.

Background

Traditionally, the reverse side of some gemstones is painted to enhance the appearance of the stones when set for ornamental or jewellery-making purposes.

Blue John, a rare, blue-banded fluorspar found oniy in one small hillside in Derbyshire, England is sometimes painted white on the back of the stone to improve its appearance. The white colour provides a contrast with the natural colours found in the stone.

The painted stone may then be mounted on a metal layer, comprising for example silver or gold.

Some manufacturers produce Blue John doublets' or triplets'. In the case of a doublet, a thin slice of the stone is fixed to the back of glass, to give the impression of a domed cabochon of the stone. in the case of a triplet, a thin slice of the stone is fixed in between glass and another backing material. This technique allows a thin slice of the stone to be used instead of a thicker cabochon, thus using less Blue John to create the same impression.

However, the translucent areas in Blue John doublets or triplets generally appear a flat colour. In time, the paint quite often wears away from the back of the stone, and this spoils the appearance dramatically.

The listing or discussion of a prior-published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge.

Summary

According to a first aspect of the invention, there is provided a method of manufactunng a decorative item, the method comprising adhering a layer of !iemstone to a layer of mother-of-pearl and performing a thinning operation on at least part of the layer of gemstone.

In this way, as mother-of-pearl is used as a backing material, the gemstone can be cut as thin as 1mm thick. This is only possible through the extra strength and durability gained from backing the fragile gemstone with durable mother-of-pearl.

Using mother-of-pearl as a backing material creates an attractive reverse side for a piece ofjewellery, which could be worn as a reversible alternative if desired.

At least part of the gemstone may be translucent prior to the thinning operation.

Thinning such gemstones allows more of the translucency of the gemstone to be exposed. The appearance of the gemstone is enhanced, as the natural iridescence found in the mother-of-pearl is more easily \isible through translucent areas found in the gemstone, creating a shimmering effect and displaying an array of attractive colours. In this way, a craftsman is able to use dark pieces of gemstone which would not be considered attractive with the prior art methods.

By translucent' is meant that the gemstone passes light to an extent visible by the human eye.

An area of the gemstone may be substantially non-translucent prior to the thmmng operation, the thinning operation being performed to such an extent that at least part of the non-translucent area becomes translucent. In this way, a craftsman is able to use pieces which are so dark andlor thick as to be non-translucent before the thinning operation.

A decorative item produced according to the invention benefits from cost savings and weight reduction when compared with the prior art stones backed with silver or gold. The painting step is eliminated.

The decorative item may comprise a layer of gemstone interposed between, and adhered to, two layers of mother-of-pearl, the thinmng operation comprising cutting the layer of gemstone in a plane being substantially paralle] to a major plane of the layer of gemstone, in order to produce two decorative items each comprising a layer of gemstone adhered to a layer of mother-of-pearl. in this way, strength is added when cutting such that less gemstone is wasted through breakage. Also, when cut in half, the gemstone may produce two opposite halves, which is especially useful when producing matching pairs of eamngs or cuff links,

for example.

The thinning operation may comprise contouring the layer of gemstone.

Additionally or alternatively, the thinning operation may comprise shaping the layer of gemstone.

The method may comprise adhering the layer of gemstone to the layer of mother-of-pearl prior to the thinning operation.

The gemstone may be Blue John stone According to a second aspect of the invention, there is provided a decorative item made using a method according to the invention.

The present invention includes one or more aspects, embodiments and/or features described herein in isolation and/or in various combinations whether or not specifically stated (including claimed) in that combination or in isolation.

Brief Description of the Drawings

A description is now given, by way of example only, with reference to the accompanying drawings, in which:-Figure 1 is a top view of a first decorative item; Figure 2 is a side view of the decorative item of Figure 1; Figure 3 is a side view of a second decorative item; Fture 4 is a side view of the decorattve item of Figure 3 following a finishing process.

Detailed Description

Fiaures I and 2 show a first decorative item 100. The decorative item 100 includes a layer of gemstone 12, wInch may be Blue John, supported by a layer of mother-of-pearl 14. The gemstone 12 and mother-of-pearl 14 form a composite layer. The colour of the mother-of-pearl layer 14 may be any of its available colours, i.e. io white, black lip, pink or abalone, for example paua shell. Some may prefer the appearance given by white mother-of-pearl, although depending on requirements or preferences the other colours/varieties of mother-of- pearl could be used as well as or instead of the white mother-of-pearl, thereby to offer enhancement and distinction of the appearance of the item. t5

An adhesive is used to join the two layers of stone 12, 14 together. A colourless adhesive allows a craftsman to perform finishing processes mcluding thinmng, cutting, setting and polishing the composite layer into different shapes, for decorative items and jewellery. Suitable adhesives which may be used include those which may be hardened by exposure to ultraviolet light e.g. by placing under an ultraviolet lamp, for example LOCTITE (which may be subject to trademark registration) 366 (catalogue no 36660) and 350 (catalogue no 35066).

Workshop equipment associated with lapidary and stone-cutting work is used to cut, shape and polish the composite layer. The workshop equipment may include diamond-tipped saw blades, diamond and silicone carbide belts and wheels, and also felt and calico polishing wheels used in conjunction with different types of stone polish. Such workshop equipment may be standard lapidary machines, or these which are customised versions of standard machines, or mechanise specifically designed for the purpose. The workshop equipment allows diamond belts, wheels and blades to be used in the cutting and polishing of the stones mentioned. The machines have a water-feed to cool and lubricate the stones during cutting. If the stones were not cut in water they could be damaged by heat and friction during the cutting process on diamond tools.

Firstly, flat surfaces are created on each of the gemstone and mother-of-pearl layers 12, 14 using the workshop equipment. The gemstone layer 12 and mother-of-pearl layer 14 are then ioined together using adhesive, and once bonded the two layers 12, 14 can be worked into different shapes and thicknesses by craftsmen using the workshop equipment, with the purpose of thinning the composite layer 12, 14 to allow the mother-of-pearl 14 to be visible through the translucent gemstone 12. The thickness of the gemstone layer 12 is decided by the craftsman but, with Blue John for example, would usually range from 1mm upwards, depending on the effect required in each piece.

Another approach, as shown in Figures 3 and 4, is to bond first and second mother-of-pearl layers 14, 16 respectively to both sides of a layer of gemstone 12, and then cut the composite layer 12, 14, 16 down the centre using a diamond tipped saw blade, thus creating two matching halves which can then be worked into a required shape. Figure 3 shows a portion 18 to be removed from the gemstone layer 12 of a decorative item 200. The portion 18 lies in a plane being substantially parallel to a major plane of the layer of gemstone 12. Figure 4 shows the resulting two decorative items, 200a and 200b. The first decorative item 200a includes the second layer of mother-of-pearl 16 adhered to a layer of gemstone 1 2a, and the second decorative item 200b includes the first mother-of-pearl layer 14 adhered to a second layer of gemstone 1 2b. The use of mother-of-pearl allows a thinner slice of gemstone to be cut down the centre than would normally be possible due to the extra strength provided. Using Blue John, for example, it is feasible for a slice as thin as 3mm to be cut using a 1mm thick blade.

It should be noted that all measurements are approximate as gemstones are worked by hand by craftspeople, and there are always natural tolerances to be aware of.

Another approach is to use the lapidary equipment to produce a shaped piece of gemstone, for example a cabochon, and then cut the gemstone to size and set the back of it to mother-of-pearl.

The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features. to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features io solve any problems disclosed herein, and without limitation to the scope of the claims. The applicant indicates that aspects of the present invention may consist of any such individual feature or combination of features. In iew of the foregoing description it will be e\'ldent to a person skilled in the art that various modifications may be made within the scope of the invention.

Claims

1. A method of manufacturing a decorative Hem, the method comprising adhering a layer of gemstone to a layer of mother-of-pearl and performing a thinning operation on at least part of the layer of gemstone.

2. The method of claim I wherein at least part of the gemstone is translucent prior to the thinning operation.

3 The method of claim I wherein an area of the gemstone is substantially non-translucent prior to the thinning operation, the thinning operation being performed to such an extent that at least part of the non-translucent area becomes translucent.

4. The method of any preceding claim wherein the decorative item comprises a layer of gemstone interposed between, and adhered to, two layers of mother-of-pearl, the thinning operation comprising cutting the layer of gemstone in a plane being substantially parallel to a major plane of the layer of gemstone, in order to produce two decorative items each compnsmg a layer of gemstone adhered to a layer of mother-of-pearl.

5. The method of any preceding claim wherein the thinning operation comprises contouring the layer of gemstone.

6. The method of any preceding claim wherein the thinning operation comprises shaping the layer of gemstone.

7. The method of any preceding claim comprising adhering the layer of gemstone to the layer of mother-of-pear] prior to the thinning operation

8. The method of any preceding claim wherein the gemstone is Blue John stone

S

9. A method substantially as hereinbefore described with reference to, and/or as i11usated in, any one or more of the accompanying drawings.

10. A decorative item made using a method accordmg to any one of claims I to 9