cryptoperthite

mineral

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Last updated

June 25, 2026

Quick Summary

Cryptoperthite is a type of alkali feldspar mineral. It is characterized by intergrown crystals of sodium-rich feldspar (albite) and potassium-rich feldspar (orthoclase or microcline).1

In cryptoperthite, these intergrowths are of submicroscopic dimensions, meaning they are too small to be seen with the naked eye or even a standard microscope. Their presence and separation can only be detected through advanced techniques like X-ray diffraction or electron microscopy. The name "cryptoperthite" itself suggests this hidden or microscopic nature.21

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perthite
…distinguishable only microscopically, and in cryptoperthite the crystals are so small that the separation can be detected only by X-ray diffraction. Perthite was originally thought to be a single mineral, described at a locality near Perth, Ontario, from which its name is derived.
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…distinguishable only microscopically, and in cryptoperthite the crystals are so small that the separation can be detected only by X-ray diffraction. Perthite was originally thought to be a single mineral, described at a locality near Perth, Ontario, from which its name is derived.
Read More