chemical composition Mg(OH)2. MgO content is 69.12% and H2O content is 3.88%. Sometimes the isomorphic elements Fe, Mn and Zn are high.
tripartite crystal system with crystal structure; Layered structure-brucite type (Figure 18-25); ; a=.313nm，c=.474nm； Z=1。
morphologically symmetric m. Slab-shaped or blade-shaped. Common flaky aggregates. Sometimes called fibrous aggregate, it is called "brucite".
fig. 18-25 crystal structure of brucite
The two layers of hydroxyl groups are hexagonal and densely packed, and magnesium ions fill all octahedral gaps between them, forming the structural layer of [mg (OH) 6] coordination octahedron; The two layers of hydroxyl ions in contact between the structural layer and the structural layer are also approximately hexagonal and densely packed, but the octahedral gap formed is not filled with cations; There are ionic bonds in the structural layers, and the structural layers are connected by hydrogen bonds
Physical properties are white and light green, and those containing manganese or iron are reddish brown; Stripes are white; Gloss of glass, pearl or silk. Hardness 2.5; Cleavage {1} is extremely complete; Cleavage sheet is flexible. The relative density is 2.3 ~ 2.6. It is pyroelectric.
The genesis and occurrence of typical low-temperature hydrothermal altered minerals are found in serpentine or dolomite.
The identification features are flaky, low hardness and {1} extremely perfect cleavage. It is easily soluble in hydrochloric acid and distinguished from talc, pyrophyllite and gibbsite.
mineral raw materials mainly used for extracting magnesium. Fibrous brucite is an important nonmetallic mineral material and an ideal substitute for chrysotile.