Howlite
Howlite · Decorative Stone and Semi-Precious Gemstone
Crystal System
Monoclinic; typically occurs as massive, nodular, or compact forms, rarely as distinct micro-crystals
Mineral Group
Borates
Chemical Formula
Ca2B5SiO9(OH)5
Formation Process
Sedimentary, forming as evaporite deposits in boron-rich saline lakes and playas through chemical precipitation
About This Crystal
Spherical polished beads showing an opaque white to chalky white base color with intricate, web-like dark grey to black veins running through them, creating a marbleized appearance
Physical Characteristics
Opaque white color with dark matrix veins, white streak, sub-conchoidal to uneven fracture, no distinct cleavage, specific gravity of approximately 2.53 to 2.59, brittle tenacity, and often exhibits weak yellowish or orange fluorescence under ultraviolet light
Optical Properties
Biaxial positive with refractive indices around 1.583 to 1.605, doubly refractive, and displays no pleochroism due to its opaque and massive nature
Hardness & Durability
Origin Region
Nova Scotia (Canada), California (USA), Germany, and Pakistan; forms in evaporite deposits
Hardness & Durability
Mohs hardness of 3.5, making it relatively soft and easily scratched by a knife or quartz; lacks high durability and requires careful wear in jewelry
Care & Maintenance
Clean with warm soapy water and a soft cloth, avoid ultrasonic and steam cleaners, harsh chemicals, and prolonged exposure to acids; store separately to prevent scratching from harder stones
Rarity & Value
Common and widely available, generally inexpensive and affordable; frequently dyed blue to imitate turquoise (known as turquenite)
Special Characteristics
Porous structure which readily accepts dyes, commonly treated to simulate more expensive turquoise or gemstone materials
Lore & History
Discovered in Nova Scotia in 1868 by Henry How, a Canadian chemist and mineralogist; widely used in modern crystal healing as a stone of supreme calm, stress relief, and to aid with insomnia, traditionally associated with the crown chakra