Magnesium silicate

Description

Any of several silicate compounds containing magnesium. For example:

• Magnesium silicate, MgSiO2
• Magnesium metasilicate, MgSiO3, occurs in nature as enstatite and chinoenstatite.
• Magnesium orthosilicate, Mg2SiO4, occurs in nature as forsterite.
• Magnesium trisilicate, Mg2Si3O8, occurs in nature as Meerschaum, and Sepiolite.
• Serpentine, 3MgSiO3-5H2O, occurs in nature as antigorite and Chrysotile (asbestos).
• Hydrous magnesium silicate, Mg3Si4O10(OH)2, occurs in nature as Steatite, and Talc.

These minerals tend to be inert and many are used as a fillers in paints, papers and crayons. They may also be used as fireproofing materials and as abrasives.

Synonyms and Related Terms

magnesium metasilicate; magnesium orthosilicate; magnesium trisilicate; serpentine; hydrous magnesium silicate; silicate de magnésium (Fr;); Magnesiumsilikat (Deut.)

Risks

• Respirable dust from these minerals is toxic.
• Noncombustible.

Physical and Chemical Properties

• All are insoluble in water and ethanol.
• Refractive Index = MgSiO2=1.651, 1.654, 1.660

Comparisons

Properties of Common Abrasives

Resources and Citations

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982

• The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 5727

• CRC Handbook of Chemistry and Physics, Robert Weast (ed.), CRC Press, Boca Raton, Florida, v. 61, 1980 Comment: ref. inde for MgSiO2=1.651, 1.654, 1.660