mineral

Howlite

Howlite (Ca2B5SiO9(OH)5)

Hardness: 3.5 on Mohs scale; Color: White to milky white with grey or black dendritic veining; Luster: Sub-vitreous to earthy; Crystal Structure: Monoclinic; Cleavage: None; Specific Gravity: 2.53-2.59

Hardness: 3
Color: White to milky white with grey or black dendritic veining
Luster: Sub-vitreous to earthy

Identified May 30, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed in evaporite deposits, typically in arid environments where boron-rich waters evaporate. It is often found in nodular masses rather than distinct crystals.

Uses & applications

Primarily used for decorative carvings, beads, and jewelry. It is frequently dyed blue to imitate turquoise or red to imitate coral due to its porous nature.

Geological facts

Named after Henry How, a Canadian mineralogist who first described it in 1868 in Nova Scotia. In its natural form, it is sometimes called 'white turquoise' or 'sacred buffalo stone'.

Field identification & locations

Identify by its waxy luster and distinctive grey spider-web veining. It is much softer than true turquoise or quartz. Commonly found in California, USA and Nova Scotia, Canada.