Boric oxide

Jump to: navigation, search


A colorless crystalline compound used in metallurgy and in the manufacture of heat-resistant (borosilicate) glassware. Boric oxide is obtained from boric acid, borax, sodium borate, or colemanite. It is used in combination with silica as a flux for glazes.

Synonyms and Related Terms

boron oxide; boric anhydride; boron trioxide; boron sesquioxide

Chemical structure

Boric oxide.jpg

Other Properties

Soluble in ethanol, hot water.

Composition B2O3
CAS 1303-86-2
Melting Point 450
Density 2.46
Molecular Weight mol. wt. = 69.6
Boiling Point 1500

Hazards and Safety


LINK: International Chemical Safety Card

Sources Checked for Data in Record

  • Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
  • Henry Hodges, Artifacts: An Introduction to Early Materials and Technology, Ronald P. Frye, Kingston, Canada, 1988
  • Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997