What Is The Crystal?

I. Composition of crystal

Crystal is a rare mineral, a type of gemstone, quartz crystalline, belonging to the quartz group in mineralogy. The main chemical component is silicon dioxide, with the chemical formula SiO2.

When pure, it forms colorless and transparent crystals. When containing trace elements such as Al, Fe, etc., it appears pink, purple, yellow, teal, etc. Irradiated trace elements form different types of color centers, producing different colors, such as purple, yellow, teal, pink, etc. Those with associated inclusions are called inclusions, such as hair crystal, green ghost, red rabbit hair, etc. The inclusions are rutile, tourmaline, actinolite, mica, chlorite, etc.

II. Formation of crystals

The conditions for crystal formation are more demanding than those for quartz in general. Firstly, there must be sufficient and stable growth space; secondly, there must be hydrothermal fluid rich in silica minerals, slightly alkaline and with low salinity; thirdly, there must be low to high temperature (1600℃-4000℃) and medium to high pressure (2-3 atmospheres); and fourthly, there must be a certain growth time to produce crystals. In nature, developed joints and fractures and faults are good spaces for crystal growth. Granite development or strong metamorphism can provide sufficient hydrothermal fluid, which itself has a good temperature and pressure. The time factor is more readily available, so crystal production is more widespread on Earth .

Crystals are often produced in the form of clusters and cavities, with cavities generally found in igneous and basaltic rocks formed by volcanic eruptions in very thick lava flow layers. When silica-rich fluids enter the thin lava pores and the temperature and pressure conditions are right, crystals and other minerals will be crystallized and precipitated.

III. Crystal production origin

The endogenous deposits of crystals are pegmatitic, hydrothermal and siliciclastic, and exogenous deposits are commonly found in alluvial mines. Gem-quality crystals are mainly produced in crystal caves or pegmatite veins, and are found in almost all parts of the world. For example, Madagascar, Zambia, Brazil, Germany, Russia, Myanmar, Afghanistan, etc.