adularia

American

[aj-uh-lair-ee-uh] / ˌædʒ əˈlɛər i ə /

noun

Mineralogy.

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

adularia British

/ ˌædjʊˈlɛərɪə /

noun

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of adularia

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

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

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

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023