Formula : CaMn2+[Si2O6]
System: monoclinic Hardness:6 Rarity:not common
Strunz id:VIII/F.1-70 -
SILICATES
Name origin: Named in 1932 by Waldemar Theodore Schaller in honor of Albert Johannsen [Belle Plaine, Iowa December 3, 1871 - January 11, 1962 Winter Park, Florida, USA], Professor and petrologist, University of Chicago, Chicago, Illinois, USA. Johannsen contribution are noteworthy. He established quantitative definitions of rock analysis and rock classifications as well as redesigning the petrographic microscope. His five volume Petrography of the Igneous Rocks is a classic in petrography.
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