Kernite

Crystal system · Monoclinic

Kernite is a borate mineral recognized among collectors for its crystal form and distribution, with known Chinese sources.

Kernite specimen
Photo: Andrew Silver · Public domain via Wikimedia Commons

About Kerniteextended article

⚠ Safety & Handling
💧water-sensitivehigh
Borate; alters with humidity.
Handling: Sealed dry case.
Information provided in good faith. Consult local hazmat regulations for transport and disposal. Severely hazardous specimens may require special storage cabinets.
Mohs 2.5–3
Vickers (~) 170 HV
Knoop (~) 185 HK
Geological setting
SedimentaryEvaporite
Element composition by mass

Formula: Na₂B₄O₆(OH)₂·3H₂O · molar mass: 237.24 g/mol

O 60.69%
Na 19.38%
B 18.23%
H 1.7%

Computed from atomic weights (IUPAC 2021). Site-occupancy groups (Fe,Mn) split equally.

Mohs Hardness 2.5–3

Kernite sits at 2.5–3 on the Mohs scale — can be scratched by a steel knife.

Colors:
Streak
White
Crystal system
Monoclinic
BoratesBorates
TL;DR · 1 min read
Kernite (Na₂B₄O₆(OH)₂·3H₂O) is a hydrated sodium borate and the principal industrial ore of boron at the famous Boron Mine (Kern County, California) — supplying much of the world's boron used in glass, ceramics, and detergents. Discovered in 1926, Kernite forms massive aggregates with prismatic to columnar crystal habit.

Kernite (Na₂B₄O₆(OH)₂·3H₂O) is a hydrated sodium borate and the principal industrial ore of boron at the famous Boron Mine (Kern County, California) — supplying much of the world’s boron used in glass, ceramics, and detergents. Discovered in 1926, Kernite forms massive aggregates with prismatic to columnar crystal habit.

More minerals to explore

About Kernite

Kernite is a borate mineral in the kernite group and has the chemical formula Na2B4O6(OH)2·3H2O. It crystallizes in the monoclinic system and is relatively soft, requiring careful handling.

Identification & care

Crystals commonly develop as prismatic, coarse cleavage masses; fibrous on cleavage surfaces. Its color is typically colorless and white. The luster is vitreous to silky, the streak is white, and specimens range from transparent to translucent. The cleavage is perfect {100} and {001} — two perfect cleavages, prismatic. The fracture is splintery, which aids identification.

Collector context

Collector notes

For collectors, Kernite is a benchmark crystalline species. Kernite has known Chinese occurrences in Tibet.

Frequently asked questions

What is Kernite?

Kernite is a borate mineral recognized among collectors for its crystal form and distribution, with known Chinese sources.

What crystal system does Kernite belong to?

Kernite crystallises in the Monoclinic crystal system.

References & databases

Mindat.org is the world’s largest open mineralogy database. Our descriptions are written independently and fact-checked.