Gemstone

#The present invention relates generally to the field of gemstones and more particularly, to a square gemstone with concave portions.

#The prior art related to gemstones includes the following U.S. patents.

#U.S. Pat. No. 5,970,744 to Greef for a Cut Cornered Square Mixed-Cut Gemstone shows a gemstone with a step-cut crown, with two steps and a table, a girdle and a pavilion. The crown and pavilion are substantially square with four equal sides and corners about one-third the length of the sides. The pavilion sides and corners are defined by eight rib lines which extend substantially continuously from the girdle to a culet.

#Other important objects and advantages of the invention will be apparent from the following detailed description of the invention taken in connection with the accompanying drawings in which:

#FIG. 1 is a top plan view of a gemstone in accordance with the present invention;

#FIG. 2 is a side elevation view of the gemstone of FIG. 1, taken along the line 2-2 of FIG. 1;

#With reference to the drawings wherein like numerals indicate like elements throughout, there is shown in FIGS. 1-5 a gemstone 5 in accordance with the present invention. The gemstone 5 includes four equal concave portions 91, 92, 93, 94, a table 10 and a girdle 100. As is best shown in FIG. 1, the table is about 67 to 73% of the diameter. The girdle lies substantially in a plane which is defined as the girdle plane and which is generally denoted by the reference numeral 100. The gemstone 5 also includes a lower portion generally designated by the reference numeral 102 which is below the girdle plane 100. The lowest point or inlet is designated by the reference numeral 104.

#The upper portion of the gemstone 5 includes two stair portions which form the crown.

#In FIG. 1, the distance between points A and B is about 65 to 75% of the distance between the points C and D. Facet 10 is the table of the gemstone 5.