What is Cryptocrystalline?
Cryptocrystalline Microcrystalline Macrocrystalline
Crystalline describes a naturally occurring solid that's made up of crystals. This is the definition of a mineral.
Microcrystalline is a term used in geology to describe a rock or mineral with crystals too small to be seen with the naked eye. Although microscopic these crystals can usually be seen when magnified.
Cryptocrystalline describes a rock or mineral whose crystals are so small they're difficult to see even with powerful magnification.
The prefix crypto comes from Latin meaning 'hidden' or 'secret'.
Although not really accurate, cryptocrystalline and microcrystalline are often used interchangeably when describing any rock or mineral whose crystals cannot be seen with the naked eye.
Microcrystalline should not be confused with macrocrystalline. This word describes crystals that can be clearly seen. An example of macrocrystalline crystals can be see in an amethyst geode.