Chrome diopside is a chromium-rich, transparent to translucent variety of gemstone-quality calcium magnesium silicate. It is one of the rarer varieties of diopside. Despite the widespread belief that green gemstones are common, naturally occurring green gemstones are actually quite rare.With chrome diopside, it is common for color to steadily darken as the size of the stone increases. Chrome diopside is colored by chromium and can display varying shades of green. The most desirable color is a rich, deep forest green color similar to that of tsavorite garnet and chrome tourmaline. A nice medium-dark green is considered most valuable. Chrome diopside is often available in very high clarity and transparency.