Mode of access: Internet at the USGS web site. Address as of 10/24/07: http://minerals.usgs.gov/minerals/pubs/commodity/silica/index.html#myb; current access is available via PURL.
Linking Entry
Formed by the union of: Industrial sand and gravel; Quartz crystal; and: Tripoli and special silica stone.
Issued also as a ch. in the annual publication: Minerals yearbook (Online).