What are the classifications of crystals?

The classification of crystals is varied, usually can be roughly divided into three categories:

1, Crystalline Varieties

Ondays, we usually viewed by a number of hexagonal crystal pillars (hexagonal crystal system) to generate a cluster of crystal clusters, is a Crystalline Varieties of the Crystalline Varieties, such as white crystal, amethyst, citrine, pink crystal, hair crystal, tiger's eye and so on belong to this type of crystal. Amethyst, citrine, pink crystal, hair crystal, tiger's eye and so on belong to this kind.

2, Crypto crystalline Varieties

Cryptocrystals appearance is a piece, not into the hexagonal crystal clusters, but they also belong to the hexagonal crystal system. However, we cannot see their hexagonal crystals with the naked eye because the size of the crystals is extremely small, and it takes a microscope to see the hexagonal crystals. These crystals are very smooth because of the "hydrated silica" that fills in between the crystals, and agate belongs to this category.

3. Special Varieties

These crystals are very different from ordinary crystals, and are difficult to be categorized as cryptocrystalline or cryptocrystalline, so they are categorized as special varieties. For example, the Skeeton Crystal (Bone Crystal) with its oddly jagged crystals, and the Phantom Crystal (Phantom Crystal), which has a pattern of mountains and water and stars within the crystal, are all categorized as this type of crystal. These crystals are categorized as special crystals.

Extended Information:

Types -

The most important distinction between crystal types is between the macrocrystalline (individual crystals visible to the naked eye) and the microcrystalline or cryptocrystalline varieties (aggregates of crystals visible only under high magnification). Cryptocrystalline variants are translucent or mostly opaque, while transparent variants tend to be large-grained.

Chalcedony is a cryptocrystalline form of silicon dioxide, consisting of crystals and tiny ****-growths of its monoclinic polycrystalline morganite. Other opaque gemstone varieties of crystal or mixed rocks that include crystals, often including contrasting bands or color patterns, are agate, carnelian, onyx, bloodstone, and jasper.

Crystals traditionally known as rock crystals or clear crystals are colorless transparent or translucent and are often used in hard stone carvings such as Lothair crystals. Crystals vary in color when they contain impurities; colorless transparent crystals are called crystals, milky white are called milky crystals, light red are called rose crystals, purple are called amethysts, yellowish brown are called smoky crystals and tea crystals, and black are called ink crystals.

Reference:

Baidu Encyclopedia-Crystal