WO1993010685A1

WO1993010685A1 - Lapidated stone for articles of jewelry and process for manufacturing the stone

Info

Publication number: WO1993010685A1
Application number: PCT/BR1991/000026
Authority: WO
Inventors: José Salustiano Ribeiro MEDRADO FERNANDES
Original assignee: EMBRAPE - PEDRAS PRECIOSAS LTDA
Current assignee: EMBRAPE - PEDRAS PRECIOSAS LTDA
Priority date: 1991-11-25
Filing date: 1991-11-25
Publication date: 1993-06-10
Anticipated expiration: 1994-05-25

Abstract

A lapidated stone for articles of jewelry is described, including a table and comprising at least two complementary stones (1, 2) of different colours, each having a table surface (3, 4) and a junction surface (5, 6). On placing the complementary stones together, their table surfaces (3, 4) complete the table (7) of the composite stone and the junction surfaces (5, 6) are superimposed on each other so as to produce a composite stone having a complementary and continuous lapidation giving the appearance of a single stone. A process of manufacturing the composite stone is also described, comprising the steps of: providing at least two non-finished complementary stones lapidated with respective table and junction surfaces; penning the two non-finished complementary stones together and then carrying out the finishing of the complementary stones together on the pen so that the final composite stone presents a complementary and continuous lapidation to give the impression of a single lapidated stone; and removing the stone from the pen, separating the complementary stones.

Description

Title: "LAPIDATED STONE FOR ARTICLES OF JEWELRY AND PROCESS FOR MANUFACTURING THE STONE".

The present invention refers to a lapidated stone for articles of jewelry, which is a composite of at least two complementary stones.

Composite lapidated stones are already known, for example, from GB 2110920, GB 821157 and GB 588891. Such com¬ posite stones, however, were generally designed to combine a new aesthetic appearance with the practical function of pro- viding a mounting for a sepatate central stone. Thus, patent GB 2110920 discloses a composite stone comprising a central stone mounted in a cavity formed in a surrounding outer stone. With a view to provide a secure mounting for the central stone, the outer stone is cut in two halves and then worked to create a cavity that receives the central stone in such a way that, on placing the two halves of the outer stone together with the central stone in the cavity, the latter is firmly re¬ tained in place as a result of the negative surfaces defined by the inner walls of the cavity. Although GB 2110920 also discloses an embodiment in which the outer stone may be com¬ posed of various different stones, even in the form of a mo¬ saic, the basic purpose is still to provide a mounting of special visual qualities for a different central stone mounted therein. In a similar manner, patent GB 588891 discloses an outer stone worked to present a substantially cylindrical orifice or cavity having a slightly smaller outer (upper) rim so that a different central stone can be introduced from the under side and prevented from coming out upwardly due to said smaller upper rim. The central stone is the prevented from coming prevented from coming out downwardly by means of the introduction of separate mounting elements. The result is a composite arrangement similar in principle to that of above mentioned GB 2110920.

A further composite lapidated stone arrangement is known from GB 821157 which discloses a larger stone having a table with chamfers at its edges over which other smaller outer mounting stones are seated, the smaller stones also hav¬ ing chamfers corresponding to thoseon the larger stone. The stones are maintained together by a mounting support or by ad- hesive.

As already mentioned, 'the lapidated stones known from the above patents involve one or more outer "mounting" stones for a central stone. Without doubt, such arrangements produce different aesthetic values when compared with single stones placed in conventional mountings even though they re¬ quire more complicated mounting techniques.

The present invention, on the other hand, has the object of providing a truly "composite" stone arrangement in that it substitutes a single stone of the same shape while comprising a plurality of stones that complement each other to form such single stone.

According to the present invention, a lapidated stone for articles of jewelry and including a table, comprises at least two complementary stones of different colours, each having a table surface and at least one junction surface whereby, on joining the complementary stones, the table sur¬ faces complement each other to complete said table and the junction surfaces are superimposed on one another to form a composite stone having a complementary continuous lapidation giving the appearance of a single lapidated stone.

It will be understood that the lapidated stone of the present invention has an -appearance totally different from stones known in the art since, although in all other ways it looks like a single stone, it is in fact a composite stone in which at least two of its complementary stones are of differ¬ ent colours, there being furthermore a different visual effect due to the junction surfaces which produce in depth colour transitions in the case of translucid stones. The present invention also permits relatively simple finishing operations, the process of manufacture including the steps of providing at least two non-finished complementary stones lapidated with table surfaces and junction surfaces; penning together the two non-finished complementary stones; carrying out the finishing of the complementary stones on the pen so that the final composite stone has a complementary con¬ tinuous lapidation; and removing the composite stone from the pen, separating the complementary stones.

Preferably, with the exception of the table and junction surfaces, the non-finished complementary stones are only partially lapidated on the remaining surfaces since the principal lapidation may be effected on the two complementary stones together on the pen. This process of manufacture ac¬ cording to the invention also has the advantage of permitting the use of rough stones having stains or other defects since, once the unacceptable parts are cut off and eliminated, the small remaining parts may still be used in the manufacture of larger composite stones. However, the complementary stones may be cut from fully lapidated stones prior to penning, in which case the finishing on the pen will only involve final lapidation to ensure continuity thereof.

For the manufacture of the article of jewelry it¬ self, the complementary stones can be joined and fixed to¬ gether, without the use of adhesive, by any suitable mounting technique, thus avoiding any marks or discolouring that usu¬ ally occur when stones are glued together.

The invention will be better understood from the following detailed description, given by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a composite lapidated stone constituted by two complementary stones, in accordance with a first embodiment of the present invention;

Figure 2 is a perspective view of a composite lapidated stone constituted by three complementary stones, in accordance with a second embodiment of the present invention; and

Figure 3 is a perspective view of a composite lapidated stone constituted by three complementary stones, in accordance with a third embodiment of the present invention.

Figure 1 shows a lapidated composite stone consti¬ tuted by two separate complementary stones 1 and 2 of differ¬ ent colours. The complementary stones 1 and 2 have respective table surface 3 and 4 and respective junction surfaces 5 and 6. On placing the two complementary stones 1 and 2 together, the table surfaces 3 and 4 form the table 7 of the resulting lapidated composite stone and the junction surfaces 5 and 6 come into superimposed intimate contact. It will be observed that with the two complementary stones 1 and 2 placed to- gether, the outer surfaces 8 and 9 present a continuity of lapidation to define a single uniform outer lapidated surface. Figure 2 shows another embodiment of the invention in which there are three complementary stones 10, 11 and 12, the second stone 11 being adapted to be sandwiched between the first and third complemenetary stones 10 and 12. As in the case of the lapidated stone of figure 1, the complementary stones have respective table surfaces 13, 14 and 15 which to¬ gether form the table of the composite stone. The complemen¬ tary stones also have junction surfaces - 17 on the first stone 10; 18 and 19 on opposite sides of the second complemen¬ tary stone 11; and 20 on the third complementary stone 12. The junction surfaces 17 to 20 are contiguous to their respective table surfaces 13, 14 and 15. On placing the three complemen¬ tary stones together correctly, junction surfaces 17 and 18 (which are identical) are superimposed on one another, and the other junction surface 19 of the second complementary stone 11 and the junction surface 20 of the third complementary stone 12 (which are identical) are also superimposed on each other. Once more as in the first embodiment of figure, when the three complementary stones are placed together, their outer surfaces 21, 22 and 23 present a continuity of lapidation to define a single uniform outer surface. Complementary stone 11 is of a different colour from the first and third complementary stones 10 and 12 which may or not be of the same colour as each other .

Figure 3 shows a third embodiment of the invention in which, similar to the figue 2 embodiment, there are three complementary stones 24, 25 and 26 but in this case each junc- tion surface, instead of being a single planar surface, is composed of two planar surfaces in the form of a "V" . Apart from ensuring more rigidity of the composite stone structure, this embodiment provides additional aesthetic effects. The colours of the three stones are variable in the same manner as in the figure 2 embodiment.

The various junction surfaces shown in figures 1, 2 and 3 are normal to the respective table surfaces. This, how¬ ever, is not essential, it being perfectly permissible for them to be inclined. The present invention is also concerned with a proc¬ ess for making the composite stone. Taking as an example the stone of figure 1, which comprises two complementary stones, a preferred manner of making it will now be described. Two stones of the colours and approximate desired shapes are first chosen and then cut and ground so as to have the approximate shapes and appearance of the two complementary stones 1 and 2, the respective table surfaces 3 and 4 and junction surfaces 5 and 6 being ground at this time. These surfaces are made smooth and flat whereby the two stones may be placed together with their table surfaces complementing each other to form a single table plane and with their junction surfaces perfectly fitting one another in mutually superimposed relationship. The composite thus formed will have an outer form very approxi¬ mately similar to that of the desired final composite stone. In the next stage and in a manner similar to usual techniques, the stone is "penned", that is to say, its table is adhered using a special adhesive or seal to the end of a small wooden rod or "pen", to permit the following phases of lapidation to be executed. In the present case, obviously, the two semi-lapidated complementary stones are ahered to¬ gether on the pen with the two junction surfaces in mutual contact as mentioned above and with the two table surfaces forming the table of the composite stone.

Once penned, the composite stone is submitted to the final stages of lapidation, which means that the two comple¬ mentary stones are workedosta. simultaneously together so as to guarantee a perfect continuity and uniformity in the final lapidation, independently of the type of lapidation being car- ried out (cabochon in the composite stone of figure 1).

Finally, the composite stone is removed from the pen in a conventional manner, that is to say, by applying heat to melt the seal, and the two complementary stones 1 and 2 are separated and cleaned with alcohol. Although the method of manufacture has been de¬ scribed with respect to a composite stone comprising two com¬ plementary stones, the same process may be used for stones constituted by any desired number of complementary stones.

It will therefore be understood that the composite stone may be made in such a way that the complementary stones are submitted to final lapidation together in the form of a single stone, thus avoiding any failures of continuity or uni¬ formity that might appear if they were to be lapidated sepa¬ rately and then only joined later at the time of mounting. The lapidated stones of the present invention may comprise any desired number of complementary stones and be lapidated in any desired manner, with or without faceting. The complementary stones do not all need to be of different colours, it being sufficient that at least two of them are of different. Similarly, the junction surfaces are not necessar¬ ily planar provided that they are smooth and fit each other precisely without any air gaps. As mentioned above, they may also be inclined rather than normal with respect to the table surfaces. It should therefore be understood that the scope of the present invention should not be limited by the above spe¬ cific description of the drawings, but rather only by the terms of the following claims.

Claims

1. Lapidated stone for articles of jewelry and in¬ cluding a table, characterised by comprising at least two com¬ plementary stones (1,2; 10,11,12; 24,25,26) of different colours, each having a table surface (3,4; 13,14,15) and at least one junction surface (5,6;17,18,19,20) whereby, on join¬ ing the complementary stones, the table surfaces (3,4; 13,14,15) complement each other to complete said table (7;16) and the junction surfaces (5,6; 17,18,19,20) are superimposed on one another to form a composite stone having a complemen¬ tary continuous lapidation giving the appearance of a single lapidated stone.

2. Lapidated stone according to claim 1, characterised by comprising first (10;24), second (11;25) and third (12;26) complementary stones so that the second comple¬ mentary stone (11;25) may be sandwiched between said first (10;24) and third (12;26) complementary stones, each of said first and third complementary stones having a single junction surface (17,20) respectively adaptable to two respective junc- tion surfaces (18,19) of the second complementary stone (11,-25).

3. Lapidated stone according to claim 1 or 2, characterised in that said junction surfaces (5,6; 17,18,19,20) are planar.

4. Lapidated stone according to claim 1 or 2, characterised in that each of said junction surfaces comprise two planar surface sections forming therebetween a "V¹.

5. Process of manufacturing a lapidated stone, characterised by the steps of providing at least two non- finished complementary stones lapidated with table surfaces and junction surfaces; penning together the two non-finished complementary stones with said junction surfaces in intimate contact; carrying out the finishing of the complementary stones on the pen so as to define a final composite stone hav- ing a complementary continuous lapidation; and removing the composite stone from the pen, separating the complementary stones .

6 Process according to claim 5, characterised in that said non-finished complementary stones are partially lapidated.