Mtorolite (Chrome Chalcedony)

SiO2 with Cr - Mohs Hardness: 6-6 1/2.  Chrome chalcedony found in an ancient Roman gem collection may have come from one of the chromium deposits in what is now Turkey. Present commercial production comes from Zimbabwe under the trade name "mtorolite", and from Bolivia under the trade name "chiquitanita".
Abstract/Description: SiO2 with Cr - Mohs Hardness: 6-6 1/2. Chrome chalcedony found in an ancient Roman gem collection may have come from one of the chromium deposits in what is now Turkey. Present commercial production comes from Zimbabwe under the trade name "mtorolite", and from Bolivia under the trade name "chiquitanita".
Subject(s): Zimbabwe, Africa
environmental sciences