Chrome tourmaline is a distinct variety of tourmaline called chrome dravite, found in East Africa. Chrome tourmaline owes its vivid green hue to trace amounts of chromium and vanadium. These are the same elements that give emerald and tsavorite garnet their distinctive pure green hues.
Like emerald and tsavorite garnet, fine chrome tourmaline is a visually pure forest green with slightly yellowish to bluish secondary hues. The blue will normally show itself in incandescent light, the yellow will be more visible in daylight. A blue secondary hue is preferred to yellow.
Chrome tourmaline is quite rare generally, and particularly rare in gems weighing over one carat. A stone of fine quality over one carat is very rare. Therefore, the collector should expect a large percentage increase in the price of stones in carat-plus sizes.