Overview

Magnesium silicate hydroxide (mag-NEE-zee-um SILL-uhkate hye-DROK-side) is also known as hydrated magnesium silicate, hydrous magnesium silicate, magnesium silicate hydrous, talc, talcum, and soapstone. It belongs to a large family of magnesium silicates that occur in nature. Magnesium silicates contain at least one magnesium ion and one or more silicate (SiO₃) ions, and often contain one or more molecules of water of hydration. Other members of the family include magnesium metasilicate (MgSiO₃), magnesium orthosilicate (Mg₂SiO₄), magnesium trisilicate (Mg₂Si₃O₈), and magnesium trisilicate pentahydrate (Mg₂Si₃O₈·5H₂O).

Key Facts

Other Names:

See Overview.

Formula:

Mg₃Si₄O₁₀(OH)₂

Elements:

Magnesium, silicon, oxygen, hydrogen

Compound Type:

Hydrated salt(inorganic)

State:

Solid

Molecular Weight:

379.27 g/mol

Melting Point:

1500°C (2700°F); begins to lose water of hydration above 900°C (1600°F)

Boiling Point:

Not applicable

Solubility:

Insoluble in water and most organic solvents

The naturally-occurring...