Silicates: Serpentine

Composition: Mg₃Si₂O₅(OH)₄; some iron and aluminium may replace magnesium

Crystal system: Monoclinic; massive or fibrous aggregates

5.24.1
fibrous serpentine (chrysotile asbestos)
Zimbabwe

Properties:

• Greasy to silky lustre
• Green color; sometimes brownish
• White streak
• Knife scratches easily to not at all (Mohs Hardness 4-6)
• Average density
• Cleavage not usually apparent
• Uneven to smooth fracture
• Not ferromagnetic
• Does not react with hydrochloric acid (HCl)

Occurrence:

Serpentine forms by the hydrous alteration of magnesium-rich igneous rocks such as pyroxenites and peridotites.

5.24.2 fibrous serpentine (chrysotile asbestos) Zimbabwe	5.24.3 massive serpentine with bastite Pine Mountain south east Qld Australia

Asbestos is a name used for a number of fibrous minerals including serpentine and various amphiboles that are valued for their strength and resistance to heat and corrosion. Demand for these minerals has declined as the health impacts of their use have become better known; however, other mineral and synthetic substitutes do not always have identical properties and may also have as yet undocumented health effects.

5.24.4
massive serpentine with bastite
Pine Mountain
south east Qld Australia