Cristobalite

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Description

A translucent quartz mineral named after Cerro San Cristobal, Mexico where it was first identified in 1887. Cristobalite is a natural, refractory material formed in volcanic rock. It can be made synthetically when quartz is heated above 1050 C. Small amounts of cristobalite in a ceramic glaze formula minimize crazing. Opals contain masses of microscopic cristobalite crystals.

Synonyms and Related Terms

cristobalita (Esp.); cristobalite (Fr., Port.)

Other Properties

Luster=Glassy Streak = white Nonfluorescent

Composition SiO2
CAS 14464-46-1
Mohs Hardness 6.5
Density 2.2
Refractive Index 1.485-1.487

Additional Information

WebMinerals: Cristobalite

Comparisons

Properties of Common Gemstones


Sources Checked for Data in Record

  • G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 647
  • Robert Fournier, Illustrated Dictionary of Practical Pottery, Chilton Book Company, Radnor, PA, 1992
  • Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997