adularia

[ aj-uh-lair-ee-uh ]

noun

, Mineralogy.

1. a sometimes opalescent variety of orthoclase formed at a low temperature.

adularia

/ ˌædjʊˈlɛərɪə /

noun

1. a white or colourless glassy variety of orthoclase in the form of prismatic crystals. It occurs in metamorphic rocks and is a minor gemstone. Formula: KAlSi 3 O 8

Word History and Origins

Origin of adularia¹

1790–1800; < Italian < French adulaire, named after Adula a mountain group in Switzerland; -ary

Word History and Origins

Origin of adularia¹

C18: via Italian from French adulaire, after Adula, a group of mountains in Switzerland

Example Sentences

But one of the prettiest though commonest gems in the island is the "Moon-stone," a variety of pearly adularia presenting chatoyant rays when simply polished.

From Project Gutenberg