mineral
Feldspar crystal twin
Orthoclase / Microcline (KAlSi3O8)
AI-generated identification · may be incorrectHardness 6 on Mohs scale, typically cream to pink or tan in color, vitreous to pearly luster, monoclinic or triclinic crystal system with good prismatic cleavage.
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Physical properties
Hardness 6 on Mohs scale, typically cream to pink or tan in color, vitreous to pearly luster, monoclinic or triclinic crystal system with good prismatic cleavage.
Formation & geological history
Forms during the slow cooling of silica-rich magma in pegmatites and granitic rocks over millions of years.
Uses & applications
Widely used in the manufacture of ceramics, glass, and as a semi-precious gemstone or mineral specimen for collectors.
Geological facts
Feldspar is the most abundant mineral group in the Earth's crust, making up about 41% of it. Twinning, as seen here in the Carlsbad or Baveno laws, is very common.
Field identification & locations
Identified by its characteristic rectangular habit, two directions of cleavage meeting near 90 degrees, and moderate hardness. Found globally in granites and pegmatites.
