Chrome gems are colored by traces of chromium, giving them a beautiful green color. Chrome green gems can range from bright green to deep forest green. Chrome gem varieties include chrome diopside and chrome tourmaline, which are available in various sizes, shapes and cutting styles.

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.

Chrome tourmaline is quite rare generally, and particularly rare in sizes 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.