Howlite
Howlite · Semi-Precious Gemstone and Decorative Stone
Crystal System
Monoclinic; typically occurs as massive nodules, tuberous aggregates, or microcrystalline veins rather than distinct visible crystals
Mineral Group
Borates
Chemical Formula
Ca2B5SiO9(OH)5
Formation Process
Sedimentary, forming typically as evaporite deposits in boron-rich saline lakes and lacustrine environments
About This Crystal
An opaque, chalky white to ivory-colored stone featuring an intricate web of dark grey, black, or dark brown matrix veins that create a spiderweb or marble-like pattern. Cut here into a faceted crystal pendant point shape.
Physical Characteristics
Color is milky white with dark matrix webbing; streak is white; cleavage is none distinct; fracture is sub-conchoidal to uneven; specific gravity is approximately 2.53 to 2.59; tenacity is brittle
Optical Properties
Biaxial positive with refractive indices around 1.583 to 1.605; birefringence is low to moderate; non-pleochroic; completely opaque with a sub-vitreous to dull or earthy luster
Hardness & Durability
Origin Region
Nova Scotia, Canada; California, USA; South Africa; and deposits in Germany and Pakistan
Hardness & Durability
Mohs hardness of 3.5, making it quite soft and easily scratched by a copper coin or knife; requires careful wear to prevent scratching and abrasion
Care & Maintenance
Clean gently with warm, soapy water and a soft cloth; avoid harsh chemicals, ultrasonic cleaners, and prolonged exposure to water or moisture due to its porous nature; store separately from harder gems
Rarity & Value
Common and widely available; relatively inexpensive, usually sold as polished stones, beads, and carved jewelry pieces; frequently dyed blue to imitate turquoise (known commercially as turquenite)
Special Characteristics
Extremely porous structure which allows it to absorb dyes easily; often fluoresces a pale yellow or yellowish-white under ultraviolet light
Lore & History
Discovered in Nova Scotia in 1868 by Henry How, a Canadian chemist and mineralogist. In crystal healing lore, howlite is associated with stress relief, calming the mind, facilitating restful sleep, and encouraging emotional expression