mineral
Howlite
Calcium Borosilicate Hydroxide (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, and a sub-vitreous to earthy luster.
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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, and a sub-vitreous to earthy luster.
Formation & geological history
Formed in evaporite deposits, primarily in boron-rich salt marshes, through the chemical precipitation of borate minerals.
Uses & applications
Widely used in jewelry making, ornamental carvings, and often dyed blue or green to imitate turquoise.
Geological facts
Howlite is extremely porous, which makes it exceptionally easy to absorb artificial dyes for jewelry manufacturing.
Field identification & locations
Easily identified by its characteristic dark spiderweb matrix set against a chalky white background. Found prominently in Nova Scotia, Canada, and California, USA.
