cryptocrystalline

American  

[krip-toh-kris-tl-in, -ahyn] / ˌkrɪp toʊˈkrɪs tl ɪn, -ˌaɪn /

adjective

Mineralogy.

1. having a microscopic crystalline structure.

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cryptocrystalline British  

/ ˌkrɪptəʊˈkrɪstəlaɪn /

adjective

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

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cryptocrystalline Scientific  

/ krĭp′tō-krĭs′tə-lĭn,-līn′ /

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

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Etymology

Origin of cryptocrystalline

First recorded in 1860–65; crypto- + crystalline

Example Sentences

Making Stone Points Points and blades chipped from cryptocrystalline rocks such as chert, flint, and obsidian make the sharpest knives, arrowheads, and spear tips, although efficiently using the latter two requires lots of practice.

From Time Magazine Archive

The structure of a flint, for example, shows that the material had so little tendency to crystallize that it remained permanently in cryptocrystalline or sub-crystalline state.

From Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 7 "Columbus" to "Condottiere" by Various

That is, the metamorphic rocks are characteristically holocrystalline, while igneous rocks are porphyritic, or cryptocrystalline.

From North America by Russell, Israel C. (Cook)

H�lleflinta under the microscope is very finely crystalline, or even cryptocrystalline, resembling the felsitic matrix of many acid rocks.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 7 "Gyantse" to "Hallel" by Various

Some concretions are amorphous, e.g. phosphatic nodules; others are cryptocrystalline, e.g. flint and chert; others finely crystalline, e.g. pyrites, sphaerosiderite; others consist of large crystals, e.g. gypsum, barytes, pyrites and marcasite.

From Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 7 "Columbus" to "Condottiere" by Various