How do I identify Thaumasite?

Thaumasite can be identified by its hardness of 3.5 on the Mohs scale, Colourless color, Vitreous luster, Hexagonal crystal system. Look for these key characteristics when examining specimens.

What color is Thaumasite?

Thaumasite typically appears in Colourless, white. Color can vary depending on impurities and formation conditions.

How hard is Thaumasite?

Thaumasite has a hardness of 3.5 on the Mohs scale. This gives it moderate hardness.

Thaumasite

A variety of Ettringite Group

Rare

Thaumasite specimen - rock identification

What is Thaumasite?

Thaumasite is a rare mineral that occurs in the form of translucent or transparent hexagonal crystals. Although very attractive, thaumasite is quite soft and fragile, so you will usually find it cut into cabochons. Its name comes from the Greek word "thaumazein," meaning "to be surprised" or "to wonder," which refers to its unusual chemical compositions.

Etymology & Origins

It was first described in 1878 in Sweden and named from the Greek, "thaumazein", to be surprised, in reference to its unusual composition with carbonate, sulfate and hydroxysilicate anions.

Optical Properties

Refractive Index: 1.467-1.505
Birefringence: 0.038
Optical Character: Uniaxial negative

Thaumasite Market Value Calculator

Estimate the market value of Thaumasite using size, quality, and finish. This preview calculator is for quick context and is not a formal appraisal.

Thaumasite Localities Map

See where Thaumasite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.

Map preview

North ZoneCentral RidgeSouth Basin

Key Characteristics

Formation of Thaumasite

It occurs as a hydrothermal alteration mineral in sulfide ore deposits and geothermal alteration of basalt and tuff. It occurs with zeolites, apophyllite, analcime, calcite, gypsum and pyrite.