The Mineral tincalconite

Most Borax specimens lose water in their structure if stored in dry areas and alter to Tincalconite. Although Tincalconite is found in a natural state, almost all specimens were transformed from Borax after being taken from the mine.

The name Tincal in ancient times applied to the mineral Borax, but now it is synonymous with Tincalconite.

Chemical Formula

Na₂B₄O₇ · 5H₂O

Color

White

Crystal System

Hexagonal

Properties

Streak White

Hardness 1

Transparency Opaque

Specific Gravity 1.88

Luster Dull

Cleavage None

Fracture Earthy

Tenacity Brittle

Other ID Marks 1) Has a sweetish, metallic taste. 2) Dissolves in water.

Crystal Habits

Always as a pseudomorph after Borax, with the same crystal forms. Also massive, grainy, and as a dehydrated powder.

3D Crystal Atlas

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Additional Information

Composition Hydrous sodium borate

In Group Borates; Hydrous Borates

Striking Features Taste and solubility

Environment Borax evaporite deposits in dry lakes of arid regions.

Rock Type Sedimentary

Other Names

Tincal

The old name for Borax. May also refer to Tincalconite.

Noteworthy Localities

Tincalconite is found most significantly at the Boron, in the Kramer District, Kern Co., California. It occurs in several other Borax localities, such as Searles Lake, San Bernardino Co., and always as a pseudomorph of Borax.

Common Mineral Associations

Borax, Ulexite, Kernite, Halite, Thenardite, Hanksite

Distingushing Similar Minerals

Tincalconite's unusual properties distinguish it from all minerals.

tincalconite Photos

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