Blue Howlite (Dyed)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
Rock Type: mineral

Physical Properties
Hardness: 3.5 on Mohs scale; Color: Artificially blue/turquoise; Luster: Sub-vitreous to earthy; Crystal Structure: Monoclinic; Specific Gravity: 2.53-2.59
Formation & Geological History
Howlite is an evaporite mineral found in sedimentary environments. While the base mineral is natural, the blue color is achieved by immersing porous white Howlite into chemical dyes to mimic turquoise.
Uses & Applications
Mainly used as a decorative stone, in costume jewelry, and as a pocket stone for collectors. It is a common substitute for genuine turquoise.
Geological Facts
Howlite was discovered in 1868 by Henry How in Nova Scotia. In its natural form, it is snowflake white with dark veins, but its porous nature makes it the most commonly dyed mineral in the gem trade.
Field Identification & Locations
Identify by looking for white patches in spiderweb cracks where dye didn't penetrate. Natural Howlite is found in the USA, Canada, and Germany. Collectors use it as an affordable alternative to rarer stones.
Identified on: 5/5/2026
Mode: Standard