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http://www.chez.com/ericlecaplain2/Realgar.html

http://www.chez.com/ericlecaplain2/Orpiment.html

http://www.mindat.org/loc-28399.html

http://rruff.geo.arizona.edu/doclib/cm/vol28/CM28_579.pdf

http://www.mineralinfo.org/mineraux/chromite.htm

http://w3.granddictionnaire.com/btml/fra/r_motclef/index1024_1.asp