How do I identify Calaverite?

Calaverite can be identified by its hardness of 2.5 - 3 on the Mohs scale, Brass yellow to silver white color. Look for these key characteristics when examining specimens.

What color is Calaverite?

Calaverite typically appears in Brass yellow to silver white. Color can vary depending on impurities and formation conditions.

How hard is Calaverite?

Calaverite has a hardness of 2.5 - 3 on the Mohs scale. This makes it a soft mineral that can be scratched easily.

Calaverite

A variety of Minerals

What is Calaverite?

Calaverite, or gold telluride, is an uncommon telluride of gold, a metallic mineral with the chemical formula AuTe2, with approximately 3% of the gold replaced by silver. It was first discovered in Calaveras County, California in 1861, and was named for the county in 1868. The mineral often has a metallic luster, and its color may range from a silvery white to a brassy yellow. It is closely related to the gold-silver telluride mineral sylvanite, which, however, contains significantly more silver. Another AuTe2 mineral (but with a quite different crystal structure) is krennerite. Calaverite and sylvanite represent the major telluride ores of gold, although such ores are minor sources of gold in general. As a major gold mineral found in Western Australia, calaverite played a major role in the 1890s gold rushes in that area.

Calaverite Market Value Calculator

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

Calaverite Localities Map

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

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North ZoneCentral RidgeSouth Basin

Key Characteristics

Formation of Calaverite

Calaverite occurrences include Cripple Creek, Colorado, Calaveras County, California, US (from where it gets its name), Nagyag, Romania, Kirkland Lake Gold District, Ontario, Rouyn District, Quebec, and Kalgoorlie, Australia.

Composition of Calaverite

Calaverite's structure has been both an object of fascination and frustration in the scientific community for many years. Goldschmidt et al. indexed calaverite 105 crystals resulting in 92 forms but needed five different lattices to index all of the faces. This led to consideration that calaverite violated Haüy's Law of Rational Indices. The introduction of X-ray diffraction did not completely solve this problem. Tunell and Ksanda in 1936 and then Tunell and Pauling in 1952 solved the C2/m general structure of calaverite. However, additional diffraction spots which they could not interpret were present in the survey. Later, transmission electron microscopy study suggested that the satellite reflections in calaverite were due to Au in incommensurately displacive modulation superimposed on the average C2/m structure. In 1988, Schutte and DeBoer solved the structure by using the 3H super space group C2/m (α O γ)Os. They also showed that these modulations consist mainly of the displacements of tellurium atoms and the observed modulations were interpreted in terms of valence fluctuations between the Au and Au. According to Schutte and DeBoer, those displacements also affect the coordination number of calaverite. In 2009, Bindi et al. concluded that the different coordination numbers associated with calaverite were indeed associated with a significant differentiation in the valence sum of Au, and that the random distribution of Ag suppresses the fluctuation of Au and Au, whereas the ordered distribution reinforces it.