mineral
Dyed blue howlite or magnesite tumbled stone
Howlite (Ca₂B₅SiO₉(OH)₅), possibly magnesite (MgCO₃), artificially dyed blue
AI-generated identification · may be incorrectTypically white to gray with a porous, opaque texture and dark natural veining; the bright blue color is dye. Hardness is about 3–3.5 Mohs, vitreous to dull luster, and irregular fracture rather than prominent cleavage.
Identified More mineral →
Explore Dyed blue howlite or magnesite tumbled stone in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Typically white to gray with a porous, opaque texture and dark natural veining; the bright blue color is dye. Hardness is about 3–3.5 Mohs, vitreous to dull luster, and irregular fracture rather than prominent cleavage.
Formation & geological history
Howlite forms as a borate mineral in evaporite-related deposits, while magnesite forms through alteration of magnesium-rich rocks; both are geologically young to ancient depending on deposit. This specimen has been cut, polished, and dyed after formation.
Uses & applications
Sold as inexpensive ornamental beads, cabochons, and tumbled stones, often marketed misleadingly as “dyed turquoise.” Typical value is about $2–$10 per piece, or $10–$30 for a small polished lot.
Geological facts
The vivid electric-blue color and web-like dark pattern are characteristic of dyed howlite or magnesite, not natural turquoise. Dye may concentrate in pores and surface cracks.
Field identification & locations
Likely sources include California and Nevada for howlite and Austria, Brazil, or China for magnesite. Test cautiously: an inconspicuous acetone swab may remove dye; hardness and acid tests can help distinguish carbonate minerals, but may damage the specimen.
