5. Marquise. The marquise cut is somewhat like an oval, but pointed at the ends: boat-shaped. It is sometimes called navette.
6. Pear-shape. This very fancy shape is cut like a marquise but with one side rounded out, giving a tear or drop-like appearance. It lends itself very well to free-hanging parts on necklaces and earclips. This cut is growing in popularity for an engagement ring.
There are many other possibilities of special faceting and fancy cuts. Stones may be cut in the shape of a kite, a keystone, a lozenge, a triangle, a half-moon or other figure. Popular among special shapes is the baguette, “little stick,” in which the stone is cut to resemble a small rod.
Increasingly in recent years, especially as a sentimental souvenir and even more in the new engagement rings, diamonds are being cut heart-shaped. This is a difficult and a costly pattern to produce since not every diamond lends itself to be cut into heart shape.
Facet cuts have come to be far more frequent than cabochon. Cabochon, usually in a medium cut, is still used for star rubies and star sapphires, as its smooth surface most lavishly displays the radiance of the star. Also, the moving band of light in the cat’s-eye and the reflection in the moonstone are at their best in cabochon. When the color in a ruby, garnet, or sapphire is beautifully deep, the curve of the cabochon takes fullest advantage of that depth and richness. Cabochon cut is also used for most opaque stones, as the opal, the turquoise, and the jade. The baguette cut is most often used around a ring, or as a frame for larger stones. Each cut has its separate beauty, and is designed to bring out the richest qualities of its gem.
Hardness of the Stones
One reason for the pre-eminence of the diamond is its indestructibility. It is by far the hardest of all stones. Setting the standard of the diamond at ten, a table has been made of descending hardness. The whole numbers on this scale are marked as follows:
| 10 | diamond |
| 9 | corundum |
| 8 | topaz |
| 7 | quartz |
| 6 | feldspar |
| 5 | apatite |
| 4 | fluorspar |
| 3 | calcite |
| 2 | gypsum |
| 1 | talc |
It is at once obvious that few of these are precious, or even semi-precious, stones. What must be noted is that this list is not a proportionate scale; that is, it indicates order, but by no means any specific degree of hardness. The difference in hardness between the diamond and its neighbor, corundum, is greater than that between corundum and talc. The best that can be said is that, as they are arranged, each one can scratch all those listed below it.
Thus there is no other stone that can scratch a diamond. The old saying “diamond cut diamond” means that two champions are evenly matched, and diamonds can be cut and polished only in this fashion. A wheel of corundum or other substance is coated with diamond dust; when this is applied to a diamond stone, an equal process of attrition takes place; diamond dust is worn off both the wheel and the stone. This dust, of course, may be used for further cutting and polishing to make the finished stone.