Adularias

Part of speech: noun

Definitions

1. A type of feldspar mineral that exhibits a unique optical property known as adularescence, creating a soft, billowy glow in the presence of light
2. A specific form of orthoclase or plagioclase characterized by its translucency and luminescent appearance, often used in jewelry
3. A mineral belonging to the feldspar group, recognized for its distinctive sheen and used for decorative purposes in gemology

Etymology: Adularia is a mineral, a glassy, often pearly variety of potassium feldspar, and its name points to a mountain in Switzerland. The name comes from Adular, the old name of the peak now called the Adula, in the Lepontine Alps of the canton of Graubünden. The stone was named after that place, the type locality where it was first described, so the word is a geographic name that became a mineral term. Here "adularias" is simply the plural form, used when speaking of more than one specimen or of the mineral in general terms.