star sapphire

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A sapphire with a polished convex surface exhibiting asterism.

Century Dictionary and Cyclopedia

1. n. Same as asteriated sapphire (see sapphire) and asteria.

GNU Webster's 1913

1. n. (Min.) a kind of sapphire which exhibits asterism.

WordNet 3.0

1. n. a sapphire that when cut shows a starlike figure in reflected light because of its crystalline structure