Tremolite
Image: John Krygier (Public domain)
Mineral NameTremolite
Chemical FormulaCa2Mg5Si8O22(OH)2
Mohs Hardness5
Crystal Systemmonoclinic
Lustervitreous
Streak Colorwhite
CleavagePerfect on {110} at 56° and 124°
Fractureuneven
Specific Gravity2.9
Colorswhite, gray, light green, colorless
Transparencytranslucent
Type LocalityBalmat, Balmat-Edwards Zinc District, St. Lawrence County, New York, USA
Mineral GroupSilicates
Usescollector, industrial
Associated Mineralscalcite, dolomite, talc, diopside, quartz, garnet
Raritycommon
Description
This specimen displays white to light gray tremolite crystals with a glimmery, criss-crossing fibrous to prismatic habit, characteristic of its amphibole structure.
Geological Context
Tremolite is a common metamorphic mineral, typically forming in impure dolomitic limestones and other magnesium-rich sedimentary rocks during regional or contact metamorphism. It can also occur in some ultramafic igneous rocks.
