The light of life is tight, and biotite gems do not contain radioactive substances harmful to human body. The gamma radiation dose of ore is the lowest in the natural level and also lower than the lowest value in the national standard. It is rich in various trace elements beneficial to human body, and has decorative and health-care functions.
Black mica
Biotite is a silicate mineral and a kind of mica mineral. Biotite is mainly produced in metamorphic rocks, but also in some other rocks, such as granite. The color of biotite varies from black to brown, red or green, and it has glass luster. The shape is plate and column. In recent years, biotite has also been widely used in decorative coatings such as stone paint.
Biotite is a silicate mineral and a kind of mica mineral.
Biotite is mainly produced in metamorphic rocks and also exists in other rocks such as granite. The color of biotite varies from black to brown, red or green, and it has glass luster. The shape is plate and column. Biotite is also widely used in decorative coatings, such as real stone paint.
The biotite single crystal is mainly short columnar or plate-shaped, with hexagonal cross-section and scale-like aggregate. Brown or black, the color becomes darker with the increase of iron content. Other optical and mechanical properties are similar to those of muscovite, and the relative density is 3.02-3. 12.
Refer to the above? Baidu encyclopedia-biotite