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Tincalconite Pseudomorph after Borax
BORATES; HYDROUS BORATES · HEXAGONAL

Tincalconite

Na2B4O7 · 5H2O

Hardness
1
Streak
White
Spec. Gravity
1.88
System
Hexagonal

About

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.

Crystal Forms & Aggregates

Other ID Marks

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

Striking Features

Taste and solubility

Environment

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

Distinguishing Similar Minerals

Tincalconite's unusual properties distinguish it from all minerals.

Photos

Crystal forms

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Pseudo-octahedral
Pseudo-octahedral with Modified Edges