mineral
Howlite
Hydrated calcium borosilicate, Ca2B5SiO9(OH)5
AI-generated identification · may be incorrectHardness of 3.5 on the Mohs scale, white or milky color with dark grey or black web-like veins, vitreous to sub-vitreous luster, and monoclinic crystal system.
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Physical properties
Hardness of 3.5 on the Mohs scale, white or milky color with dark grey or black web-like veins, vitreous to sub-vitreous luster, and monoclinic crystal system.
Formation & geological history
Formed in evaporite deposits from the evaporation of boron-rich salt lakes, predominantly found in desert environments.
Uses & applications
Commonly used for ornamental carvings, beads, and cabochons in jewelry, and frequently dyed blue to imitate turquoise.
Geological facts
Howlite was discovered in Nova Scotia in 1868 by Canadian chemist Henry How and is exceptionally soft, making it easy to carve.
Field identification & locations
Identified by its chalky white appearance, dark matrix veining, and low hardness which allows it to be easily scratched by a knife.
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Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Tumbled granite
Granite, a coarse-grained felsic intrusive igneous rock
igneous
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Granite
Granite (Phaneritic intrusive igneous rock)
igneous