Diopside: crystals on matrix

Lovely Chrome Diopside crystals, many formed in a star-shaped radiating pattern. The crystals are on a black matrix that has a slightly metallic lustre, and are very tiny - but many have a lovely clarity and deep emerald colour when viewed with a magnifying glass, suggesting that these are the Chromium form of Diopside.
Size: 4.5 x 2.5 x 1.25 cm