Opal, cristobalite, and tridymite: Noncrystallinity versus crystallinity, nomenclature of the silica minerals and bibliography

摘要

Cristobalite and tridymite are distinct forms of crystalline silica which, along with quartz, re encountered in industrial operations and industrial products. Because the International Agency for Research on Cancer has designated "crystalline silica" as an IARC Group 2A (probable Carcinogen) and quartz and cristobalite as a Group 1 (carcinogen), it is important to properly Identify and quantify the silica phase in all materials used in production and encountered in Products. Opal is a form of hydrated silica which is also encountered in industry.