Chrome diopside is a calcium magnesium pyroxene coloured a rich forest green by traces of chromium, the same element that colours emerald. That is why small stones can look remarkably emerald-like at a fraction of the price. Most of it comes from eastern Siberia in Russia, where mining is limited to the warmer months, and newer finds in Pakistan add to supply. Larger stones tend to darken, so the sweet spot is usually under two carats, where the green stays bright and lively.
At 5.5 to 6 on the Mohs scale with two directions of cleavage, chrome diopside needs a bit of care. It is best in earrings and pendants, or in rings with protective settings worn occasionally. The upside is that it is almost never treated: what you see is natural colour. It is usually faceted to make the most of its sparkle. Clean it only with warm, soapy water and a soft brush, and keep it away from ultrasonic cleaners and rough treatment.
A budget-friendly alternative to emerald's chromium green; peridot and green tourmaline can offer similar green colours.
