The common color of diopside is blue-green to yellow-green, brown, yellow, purple, colorless to white. Luster for glass luster. If chromium is present in diopside, the mineral has a green tinge, so diopside gems are often confused with other gems such as yellow-green olivine, (green) tourmaline, and chrysoberite, which of course depend on other physical differences between the minerals to distinguish them.