US2340659A - Precious stone - Google Patents

Description

Feb. 1, 1944. E 'GOLDsTElN 2,340,659v

PREC IOUSv S TONE iled May 5,r 1945 2 sheets-shame Patented Feb. 1, 1944 UNITED sTATrs PATENT oFFicE Edward Goldstein, Brookline, Mass. imputation May 5, 194s. serial No. 485,706

This invention pertains to precious or semiprecious stones, and relates more particularly to a novel arrangement of facet surfaces whereby, among othervaluable features, an improvement in brilliancy, as compared with prior practice, is obtained. For convenience in illustration, but without limitation, the invention is herein described as embodied in a brilliant cut stone, especially a diamond. In accordance with the Vbrilliant system of cutting, the general contour Customari1ythere is left between the faceted surfaces of the crown and pavilion an unfaceted and unpolished narrow band termed the girdle which extends uninterruptedly around the stone. Were this band or girdle omitted, the sloping faces of the crown and pavilion would intersect at acute angles, making the stone weak and subject to chipping at the very point at which the setting customarily engages it, at the same time forming very sharp edges and corners. Although hereto' fore considered a necessary structural feature of the stone, this rough and unpolished girdle forms a barrier to the passage of light, thus to some extend reducing refraction, and is noticeable asa gray band at the mid-portion of the stone, and by reason of its roughness tends to accumulate dirt which is very dililcult to remove.

The principal object of the `present invention is to provide a novel construction whereby the luster of an otherwise conventionally cut stone, specically a brilliant, is greatly enhanced but without producing sharp cutting edgesat this point. A further object is to provide a precious or semi-precious stone having a girdle portion so shaped as to afford the desired strength and a better anchorage for thesetting than the usual girdle. Other and further objects and advan- 'tages of the invention will be pointed out in the following more detailed description and by reference to the accompanying drawings wherein: A Fig. 1 is a plan view to large scale of a brilliant cut according to one embodiment of the present invention; j

Fig. 2 is a side elevation of the stone of Fig. 1; Fig. 3 is a fragmentary section to larger scale on the line 3-3 of Fig. 2; Fig. 4 is a view similar to Fig. a preferred construction; and

" Fig. 5 is a side elevation of the stone of Fig. 4. Referring to the drawings, the numeral I desigs claims (ci s3-a2) nates the crown portion of the stone, the numeral 2 the pavilion, 3 the table and 4 the culet. Between the crown and pavilion is the girdle 5. The crown is shown as having the conventional thirty-two facets 6 and the pavilion as` having the conventional twenty-four facets 1.

In accordance with that embodiment ofthe present invention illustrated in Figs. 1, 2 and 3, the' girdle 5 is cut and polishedtoprovide numerous facets 8. These facets 8 are polygonal, the number of sides depending upon their location relative to the crown and pavilion faces which they intersect, these girdle facets intersecting in lines 9 which are approximately parallel to the vertical axis of the stone, the facets 8 being substantially flat and disposed in planes which are approximately parallel to the axis of the stone. Preferably these facets 8 are of substantially uniform. length, circumferentially of the stone and so varranged that they form approximately a rectangular polygon. In order to avoid the formation of unduly sharp angles between adjacent facets 8 and to preserve thegeneral circular contour of the stone at the girdle portion, it has' been found desirable to have the number of facets 8 at least as great as the number of facets in the crown. Preferably the number of facets in thegirdle should exceed thos in the crown, and for greatest brilliancy, the number of facets in the crown should be such that the lines of intersection of the girdle facets will not coincide too frequently with the intersections of the crown or pavilion faces,

-for example, as here illustrated, there are two andone-half girdle faces for each crown face which adjoins the girdle. In fact, for optimum results, it is found that the girdle of a brilliantcut stone should have at least forty of the facets 8, in stones of usual commercial size, and that for larger stones this number may advantageously be.

increased. Thus, if forty facets be provided in the girdle, the total vnumber of facets is increased from the usualifty-eight to ninety-eight, the result being to intensify the normal prismatic brilliance of the stone very materially. By this procedure the usual light-absorbing, gray band at the girdle portion of the stone is eliminated and in, its place the girdle becomes a flashing band of light. However, while the girdle is thus made l but illustrating 'Y' to contribute very markedly to the light reflecting and light refracting characteristics of the stone, the girdle is still sturdy and strong, well qualified to resist chipping, and to provide good retention of the stone in its any acutely sharp edges.

While the construction `illustratedin Figs. 1 to 3 inclusive and as l above describedfprovides a stone of much greater brilliancy 'than the usual stone having an unfaceted girdle,it has been found that by the construction illustrated in Figs. 4 and5 an even greater brilllancy'is obtainable and girdle, respectively,

setting but without that the stone is much yso 'that they wouldgconverge downwardly,

` together with the provision' of better anchorage for the setting. In the arrangement shown in Figs. 4 and 5, the cutting of the crown and pavilion of the stone is conventional and such as above described. The girdle portion is provided with facets`8 corresponding generally in arrangement and number to the facets 8 above described, but in this instance these facets, instead of being substantially vertical, that is to say, in planes parallel to the aXis of the stone, are disposed in planes which are inclined, relative to the axis of the stone-in other words, the stone may be described as having a beveled'girdle, the intersections of the girdle facets convergingI toward the axis of the stone. By thus inclining these girdle facets B* so that their planes converge toward the table of the stone1 the facets 8* be-v come visible from the top of the stone, in effect forming a distinct border for the crown, and impart to the'stone the appearance of having a halo of light at its mid-portion. These inclined faces not only of themselves enhance the brilliancy of the stone, but apparently, by internal refraction and reflection, increase the'brilliancy of the regularcrown faces. A

While it is evident that the greater the inclination of these facets 8- to the vertical, the more they will become visible from the top of the stone, it appears from experiment that for best results the inclination of these facets 8 should be between 10 and 30 from the vertical; Not only d0 these inclined girdle faces, which in a sense thus become a part of the crown, add very materially to the brilliancy of the stone, but the beveled and faceted surface at this point provides a much more secure anchorage for the setting than does the ordinary girdle. The bevelled less desirable-than those above specifically described and illustrated.

In the above description reference has been made particularly to an improvement in the cutting of diamonds, but it is to be understood that the invention is applicable to the cutting of other precious stones, for example emeralds.

While certain desirable embodiments of the invention have been disclosed by way of example,

it is to be understood that the invention is n'ot necessarily limited to the precise constructions ,shown but is to be regarded as broadly inclusive of any equivalent constructions within the scope of the appended claims.

I claim: i

, 1. `A brilliant-cut. precious stone having a faceted crown and a faceted pavilion with a girdle interposed between the crown and pavilion, the girdle comprising forty or more substantially flat polished facets. l

2. A brilliant-cut precious stone having a faceted crown and pavilion with a girdle interposed between them, the girdle comprising a plurality of substantially fiat polished facets, said facets intersecting in lines approximately parallel to the axis of the stone, the number of said girdle vfacets exceeding the number of facets in the girdle makes it possible to provide a greater thickness of the setting metal at this point than is permissible when the outer surface of the girdle is substantially vertical. At the same time the angles where the tiny girdle facets intersect and the angles between the girdle facets and the faces provide a very secure grip for the metal of the setting so that the stone can neither turn nor tip in its setting. v

Since the facets 8B exceed in number the crown faces, the facets 8a are necessarily somewhat irregular in contour, but in vgeneral are vertically narrow, circumferentially elongate polygonal gures, and of substantially ferentially of the stone, and collectively form substantially a regular polygon in plan view. While I these girdle facets thus slope upwardly and inalthough the resultant girdle is, as above described, highly polished and very brilliant.

The polished girdle, whether of the type shown in Fig. 1 or that shown in Fig. 4, does not tend to collect dirt as does the unpolished girdle, so more easily kept clean than is the ordinary stone and thus its unusual brilliancy is not readily dulled by the accumulation of dirt. -While improved effects, -.practices, are obtained by inclining the vgirdle as compared with prior that is to say, such from the top ofA the stone,

facets 8* in the opposite direction,

faces are not'visible.

extent adding to the an arrangement is uniform length circumexcep't through the interveningmaterial of the Y stone, and although to some 'brilliancyofpthestone. such 3. A brilliant-cut precious stone having a faceted crown and a faceted pavilion with a girdle interposed between the crown and pavilion, the girdle consisting of forty or more substantially flat polygonal facets of approximately equal circumferential length, adjacent facets intersecting in lines which are approximately parallel to the axis of the stone. Y

4. A brilliant-cut precious stone-having a faceted crown and a faceted pavillonwith a girdle interposed between the crown and pavilion, the girdle comprising forty or more polished facets which slope upwardly and inwardly, the inclina-l tion of the girdle facets being between 10 and 30 from the vertical.

5. A precious stone having a faceted crown and a faceted pavilion with a girdle interposed between the crown and pavilion, the girdle comprising substantially fiat facets at least as great in number as the crown facets, said girdle facets converging upwardly and inwardly, the planes ofy all of the girdle facets making substantially equal angles with the axis of the stone.

6. A brilliant-cut precious stone having a faceted crown and a faceted pavilion with a girdle interposed between the crown and pavilion, the girdle comprising substantially fiat polished facets each of generally polygonal contour, there being two and one-half such girdle facets for each crown facet which adjoins the girdle, said facets being inclinedupwardly and inwardly so as collectively to form-a beveled girdle.,

7. A precious stone having a faceted crown and a faceted' pavilion with a girdle interposed between'the crown and pavilion, the girdle being upwardly and inwardly being visible from above scintilating border for the crown.

8. A brilliant-cut precious stone having a faceted crown and a faceted pavilion with a girdle interposed between the crown and pavilion, the girdle being upwardlyand inwardly sloped and comprising many smallilat facets intersecting in distinct edges, thereby providing a rmgrip for the material of the settngand resisting rotation sloped and faceted and l the stone as a distinct,

Images