- Blue stone: lapis ... - Gem, lapis ... - Stone, lapis ... - A mineral of a fine azure-blue color, usually in small
rounded masses. It is essentially a silicate of alumina, lime, and
soda, with some sodium sulphide, is often marked by yellow spots or
veins of sulphide of iron, and is much valued for ornamental work.
Called also lapis lazuli, and Armenian stone.