What is sepiolite? What is brucite?

Sepiolite is a kind of fibrous hydrous magnesium silicate, usually white, light gray, light yellow and other colors, opaque and lusterless. Some of them are shaped like clods, some of them are in the shape of a strange crust or tubercle. Under the electron microscope, it can be seen that they are made up of numerous filaments. Sepiolite has a strange feature, when they encounter water, they will absorb a lot of water and become soft, and once dry, they will become hard.


Brucite / brucite Mg (OH) 2. Hardness: 2.5. It is a kind of monocrystal with thick plate shape, which is usually a lamellar aggregate; sometimes it is a fibrous aggregate, which is called nemalite or brucite asbestos. Brucite often forms the illusion of periclase.