cryptocrystalline

[krip-toh-kris-tl-in, -ahyn]

adjective Mineralogy.

having a microscopic crystalline structure.

Origin of cryptocrystalline

First recorded in 1860–65; crypto- + crystalline

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for cryptocrystalline

Historical Examples of cryptocrystalline

That is, the metamorphic rocks are characteristically holocrystalline, while igneous rocks are porphyritic, or cryptocrystalline.
North America
Israel C. Russell

British Dictionary definitions for cryptocrystalline

cryptocrystalline

adjective

(of rocks) composed of crystals that can be distinguished individually only by the use of a polarizing microscope

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

cryptocrystalline in Science

cryptocrystalline

[krĭp′tō-krĭs′tə-lĭn, -līn′]

Having a microscopic crystalline structure, as the mineral chalcedony does.