Chrome tourmaline is a variety of tourmaline containing chromium, to which it owes its color. The color is bright green, thick, and saturated. Chromium tourmalines are brighter than verdelite and are worth several times more. It is the most expensive tourmaline after the paraiba tourmaline.
The main feature of a gem is its distinctive deep green colour. Chrome tourmaline is a collector’s stone, not because it has poor durability for jewelry, but because it`s too rare.
Unlike other types of tourmaline, chrome tourmaline is often found in small sizes: most specimens weigh less than one carat. The most significant deposits of gem-quality chrome tourmaline are in Tanzania.
Chrome tourmaline is sometimes used for cutting and jewelry inlays. Transparent tourmalines are given a stepped, fancy, or, rarely, a diamond cut. Translucent stones and specimens with a cat’s eye effect are given a cabochon cut.
Chrome tourmaline is quite ductile and not sensitive to heat, but it is prone to splitting at the boundary of the stained area, especially if it is clearly marked. When such a sharp transition from one color to another is possible, you should be especially careful, as you should grind and heat the stone carefully. Ideally, you should glue it cold.
When sanding you should not make any sharp corners on the stone, as cracks often form in such places. If a crack does appear, it should be filed away immediately and the proportions of the stone should be corrected accordingly.
Some zone-colored specimens are characterized by the fact that they inevitably fall apart despite all the precautions that have been taken. After grinding, a large and seemingly defect-free piece is obtained with only a small fraction of the weight of the original material.
Material with a homogeneous coloring usually does not cause any problems during processing. It peels quickly, on sharp corners there may be slight chipping of material. It is easily polished with aluminum oxide, tin oxide, or chrome oxide on a tin disc. You may get some scratches on the big table facets, but they can be removed by changing the polishing direction. It is better to polish the table facets on a wooden faceplate.