Gemstone -
While green is regarded as the classical tourmaline color, Tourmalines exist in more colors than any other gemstone. The most common color is a dark green, but bright green chrome tourmalines are seen, as are blue, red, pink, orange, yellow, colourless, brown, violet and black.  In fact, some tourmalines display two or more colors within the same crystal. Green tourmalines are however, the most sought-after color; the finest ranging from blue-green to dark bottle-green.

The major green tourmaline deposits are in Brazil, Namibia, Nigeria, Mozambique, Pakistan and Afghanistan. But green tourmalines of good color and transparency are a rare thing in any gemstone mine. And if, in addition, they are also free of inclusions, they are very highly coveted indeed. The most coveted Tourmaline is Chrome Tourmaline. That is the name given to the emerald green variety from Tanzania, colored by vanadium and chrome. Its color is extraordinarily beautiful, and amazingly similar to that of a fine emerald, which, after all, is among the most expensive gemstones in the world.

Green tourmalines can be cut in all kinds of different ways. However, the cutting of a tourmaline does require special care, since the color intensity of most green tourmalines is variously developed depending on the direction of growth. For this reason, dark stones have to be cut in such a way that the table is parallel to the main axis. With light stones, on the other hand, the table surface should be perpendicular to the longitudinal axis, in order to receive more depth of color. When aligning the cut, the cutter must pay great attention to these facts, otherwise the cut gemstone will end up too light or too dark.  
Compound : Borosilicate
Mohs Scale(Hardness) : 7-7.5
Found : Brazil, Namibia, Nigeria, Mozambique, Pakistan and Afghanistan