Where is Howlite found?
Ca2B5SiO9(OH)5
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Open the appHowlite occurs in specific geological environments. Knowing where to look, and in what kind of rock, is the difference between going home empty-handed and finding a great specimen.
Where to find Howlite
Nova Scotia, Canada
The type locality, where it was first discovered in 1868 by Henry How. Found in gypsum and anhydrite deposits.
California, USA
Significant deposits, particularly in the Kramer Borate Deposit in Boron, Kern County, where it is associated with other borate minerals like borax and ulexite.
Nevada, USA
Found in borate-rich evaporite basins.
Turkey
Known for its extensive borate deposits, including howlite.
Germany
Occurrences reported in some evaporite formations.
Collecting tips
- Geological Context. Look for howlite in arid regions associated with evaporite deposits, particularly near ancient lake beds or areas with volcanic activity that introduced boron into the environment. It often occurs alongside gypsum, anhydrite, and other borate minerals.
- Appearance. Search for white, opaque nodules or masses with distinctive gray or black spiderweb-like veining. The material may feel relatively light for its size due to its porosity.
- Hardness Test. Howlite is relatively soft (Mohs 3.5). A simple scratch test with a copper coin (Mohs 3.0) or a steel knife (Mohs 5.5) can help differentiate it from harder minerals. It should be scratched by a knife but not easily by a fingernail.
- Specific Gravity. Its relatively low specific gravity (2.53-2.59) can be a distinguishing feature compared to denser minerals.
Quick Check
- Color:
- White to off-white with gray/black veining
- Luster:
- Sub-vitreous to earthy
- Streak:
- White
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