Chemical formula for the SiO2. Pure colorless transparent crystal is a variant of quartz. Chemical composition containing Si-46.7%, O-53.3%. Due to contain a mixture of different things or mechanical mixed with a variety of colors. Purple and green are iron (Fe2 +) ion color, purple can also be caused by titanium (Ti4 +), the other colors caused by the color center color. In the crystal contains sand, debris-like goethite, hematite, rutile, magnetite, garnet, chlorite and other inclusions; hair crystal contains the naked eye can be like hair-like needle-shaped mineral package Body formation. (Including golden yellow or lemon color) called yellow crystal; containing manganese and titanium rose rose were called rose quartz; smoke who said smoke crystal; brown, said tea crystal; black transparent Called ink crystal; was light green called stone marrow.
Crystal crystal structure and shape:
Is a tripartite system. Crystal was prismatic and with hexagonal cone, cylindrical stripes, amethyst often angular ribbon. In nature, the crystal often produced crystal clusters, handsome in appearance.
The physical properties of crystal:
Crystal was colorless, purple, yellow, green and smoke, etc., glass luster, transparent to translucent, hardness 7, brittle, the proportion of 2.65, no cleavage, shell-like fracture, there are good ridge of the chevron. Amethyst has a clear dichroism, yellow crystal and tea crystal with weak dichroism. The luminous crystal has a strong phosphorescence. With green sand gold crystal in the long, shortwave ultraviolet radiation under the gray-green fluorescence. With cat's eye, iridescence and sand gold effect. Crystal with piezoelectricity.