Margarite

Part of speech: noun

Definitions

1. A pearly brittle mineral of the mica group, composed of calcium aluminium silicate and often found in metamorphic rocks
2. A brittle, pearly-lustred silicate mineral belonging to the mica family and rich in calcium and aluminium
3. A calcium-bearing mica mineral with a pearly sheen and brittle flakes, typically formed in metamorphosed rocks such as schists

Etymology: Margarite is a pearl-like mineral, and its name goes back to the Greek word for pearl, "margarítēs." That Greek noun is the same root behind the given name Margaret, which is a doublet of the mineral name: the two words descend from one ancient source but reached English by different routes, one as a personal name and the other as a scientific label. The mineral name adds the suffix "-ite," a standard mineralogical ending borrowed from Greek "-ítēs" and used to name rocks and minerals. So the word combines an ancient word for pearl with a modern naming convention. Its sense as a mineral is a technical coinage, not a survival from Greek usage, and it describes a brittle, pearly-lustred mica-group mineral.