mineral
Howlite
Ca2B5SiO9(OH)5
AI-generated identification · may be incorrectHardness 3.5 on Mohs scale, white or milky color with dark grey or black web-like veins, sub-vitreous to earthy luster, monoclinic crystal system.
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Physical properties
Hardness 3.5 on Mohs scale, white or milky color with dark grey or black web-like veins, sub-vitreous to earthy luster, monoclinic crystal system.
Formation & geological history
Formed as borate minerals in evaporite deposits, commonly found in sedimentary borate basins.
Uses & applications
Widely used for making beads, ornamental carvings, and often dyed blue to imitate turquoise.
Geological facts
First discovered in Nova Scotia in 1868 by Canadian chemist Henry How, after whom it is named.
Field identification & locations
Identified by its distinctive spider-web matrix and low hardness; major deposits are located in Nova Scotia and California.
