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mineraloid

American  
[min-er-uh-loid] / ˈmɪn ər əˌlɔɪd /

noun

  1. a mineral substance that does not have a definite chemical formula or crystal form.

Etymology

Origin of mineraloid

First recorded in 1910–15; mineral + -oid

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.

Opal is a mineraloid, because although it has all of the other properties of a mineral, it does not have a specific structure.

From Textbooks • Jan. 1, 2015

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

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.