This is a lovely ring and is a size N and mounted on a sterling silver shank. The diopside gemstone group is most famed for its chrome green member known in the trade as ‘chrome diopside’, but ‘star diopside’, a chatoyant black to greenish black diopside is also highly sought after and treasured by gem collectors, owing to its uniqueness. Black star diopside is sometimes traded as “Black Star of India”. Although it is typically black or blackish-green, on rare occasion, star diopside can be true green. Star diopside may sometimes be confused with similar coloured gemstones such as hiddenite, moldavite, peridot, emerald or idocrase. Black star sapphire is often confused with black star diopside, but can be easily distinguished by its hardness and the differences in asterism (the star effect).