Lapidary
The Cutting of Gemstones
Lapidary is the art of cutting and polishing gems to enhance the natural beauty. By cutting the gems, light is allowed to pass through and amplify a gem's natural refrectiveness. In a properly cut diamond, the light will pass through the top facets, reflect off the lower facets and pass back through the upper facets to the viewer. Usually a cut is decided based upon the attributes of the stone. For example, a large stone will have a different cut than an small stone. A translucent or opaque stone, such as opal or turqoise, is often cut in a dome-shame "cabochon", as there is little point in faceting if no light passes through. Although the cutting of diamonds in India had been practiced for centuries, the faceting of stones became fashionable in the fifteenth century under the influence of Louis de-Berguem.
Although most gems today are cut by machine, delicate cutting is still done by hand. Some countries are renowned for the skill in cutting gems, Holland, Belgium, Germany, Israel, India, China, and Sri Lanka to name a few.
The areas of a cut stone are identified as follows:
Table:
Top facet
Crown:
Second facet layer
Girdle:
Facet where the Crown ends
Culet:
Last and lowest facet. This can be quite wide as it will usually be in the setting
There are many cuts of stones. Each has its own distinctive style and number of cuts. Gems may be cut to enhance a certain quality, such as size or color. Also, the value of the gem may be determined by the cut.
Alphabetical List of Cuts
Baguette Cut: A cut with 17 facets. Brilliant Cut: Introduced by Peruzzi in the 17th century, this cut is one of the most common cuts currently used. Having 58 facets, it greatly enhances the luster of gems. Also currently in use are Modified Brilliant Cuts of varying facets.
Cabochon Cut: This cut has a round protuberating convex at the top, a flat back and other simple facets. In fashion since ancient times, it is becoming less used today. It is usually found in gems such as carbuncle, garnet, cat’s eye, star stone, and transparent and non-transparent gems. Sometimes it can be found in Emerald and Topaz.
Concave-Convex Cabochon Cut: The lower conclave and girdle is kept thin. This cut is usually used on stones which are extremely dark such as garnet, carbuncle and almandine. In a Hollow Cabochon Cut, the table is kept protruberating while the lower portion is kept concave.
Cushion Cut: This cut is a somewhat flat cut with its crown facets being kept parallel to the girdle facets.
Diamond Point: Octahedral gems are usually cut in this shape and polished to enhance their natural shapes.
Double Convex Cabochon: This cut has two curved convex at the top and at the bottom. However, the angles of the curves are different.
Double Cut: It has 58 facets of which 33 are crown facets and 25 are bottom facets. This cut is used for large diamonds.
Emerald Cut: Also called Step Cut or Trap Cut, it has 58 facets onsisting of 1 table, 24 crown facets, 8 girdle facets, 24 lower facets and 1 culet. It is generally used in Emerald and Yellow Sapphire (Topaz).
English Polky: This cut has 25 facets – 1 table and 24 lower facets.
French Star Cut: A cut using different variations of cuts.
Heart Cut: Cut in the shape of a heart, this cut has 65 facets. This is one of the cuts seen more seldom.
Jubilee Cut: This cut has 88 facets.
Marquise Cut: Also called the Navette Cut, it has 58 facets.
Mixed Cut: The upper portion is Brilliant Cut. The lower portion is cut using a different cut.
Modified Brilliant Cuts: These improvements on the Brilliant Cut have varying number of facets. These new cuts save on the weight of the gems and enhance the beauty of the stones even more than the standard brilliant cut. American Brilliant Cut: a cut of 84 facets. Cairo Star: This cut has 74 facets, 25 at the top and 49 at the bottom with a wide culet-type table. It is not a very attractive cut in some opinion. Eight Sided: 30 facets. English Brilliant Cut: This cut has 30 facets. Sixteen Sided: a cut of 33 facets.
Multi-Star Cut: A number of stars are cut around the table, and generally there is no culet. This cut is used specifically with yellow quartz.
Navette Cut: See Marquise Cut
Oval Brilliant Cut: As named, with a total of 58 facets.
Pear Cut: Cut in a pear shape, the number of facets can vary from 58 to 74.
Polky: With a total of only 4 facets, this consists of 1 table and 3 facets in the lower part.
Rose Cut: This cut is commonly used in small diamonds or in colored and small gems to be used in accompanying big gems. There are varying kinds of rose cuts, being: Dutch Rose: Three smaller facets at the base of each triangular facet for a total of 24 facets. Half Dutch Rose: This has 18 facets. Antwerp Rose: This has 12 facets. Double Rose Cut: Pear shaped with triangular facets, this has a rose cut at the base of each octohedron, joining two roses together at the base. This cut is also called Modern Boriolette. Cross Rose: This rose cut has 24 facets.
Simple Cabochon: The upper facet is curved while the other is smooth or flat.
Single Cut: A single cut has 17 facets – one table, eight top facets and eight bottom facets. This is usually used in small gems.
Trap Cut: See Emerald cut.
Trilliant Cut: This consists of 22 facets – 1 table, 5 crown facets, 15 triangles and 1 culet. Step Cut: See Emerald cut. Zircon Cut: As its name implies, this cut is used specifically with Zircon. The cut resembles the Brilliant Cut but has one additional set of facets.
