Howlite
Howlite · Semi-Precious Gemstone and Decorative Stone
Crystal System
Monoclinic; typically occurs in massive, nodular, or compact forms rather than distinct crystals.
Mineral Group
Borates
Chemical Formula
Ca2B5SiO9(OH)5
Formation Process
Sedimentary, forming in evaporite deposits from boron-bearing salt lakes.
About This Crystal
Opaque white or ivory-colored stone featuring a distinct web of dark grey, black, or dark brown veins in a matrix pattern, presenting a smooth sub-vitreous to dull luster.
Physical Characteristics
White to milky-white body color with a white streak, opaque transparency, uneven fracture, lacks distinct cleavage, specific gravity of approximately 2.53 to 2.59, and brittle tenacity.
Optical Properties
Biaxial (+) with refractive indices around 1.583 to 1.605, birefringence of 0.022, and non-pleochroic.
Hardness & Durability
Origin Region
Nova Scotia, Canada; California, USA; South Africa; Germany
Hardness & Durability
Mohs hardness of 3.5, making it quite soft and easily scratched by a knife or quartz, requiring careful handling when used in jewelry.
Care & Maintenance
Clean gently with warm, soapy water and a soft cloth; avoid harsh chemicals, ultrasonic cleaners, and prolonged exposure to direct sunlight or water due to its porous nature.
Rarity & Value
Common and widely available, frequently used as an affordable gemstone bead or dyed to imitate turquoise (sometimes called turquenite).
Special Characteristics
Highly porous structure that readily absorbs dyes, commonly treated to simulate more expensive stones like turquoise or red coral.
Lore & History
Discovered in Nova Scotia in 1868 by Henry How, it is traditionally associated with relieving stress, calming the mind, and overcoming anger in crystal healing practices.