CTX14AP7: Spongy growth of lustrous Gold (variety electrum) on a Quartz matrix.
The specimen comes from a well-known locality, although one that is rarely represented in collections. Its main interest lies in the fact that the Gold corresponds to the electrum variety, a natural gold-silver alloy whose silver content gives it a characteristic pale golden colour.
The specimen comes from the duplicates of the Carles Curto collection (number 1994.06)

Hornitos was one of the many mining settlements established during the California Gold Rush and is a classic locality for Gold and its variety electrum. The area developed around important gold mining operations that reached their peak during the second half of the nineteenth century.

Geologically, the gold mineralization at Hornitos is related to hydrothermal quartz veins emplaced within metamorphic rocks and serpentinites of the Sierra Nevada Foothills. These veins carried Gold and, locally, its variety electrum, precipitated from hydrothermal fluids circulating through fractures in the host rocks.
Hornitos mining district, West Belt, Hornitos, Mariposa County, California  USA

Specimen size: 1.4 × 1.2 × 1 cm = 0.55” × 0.47” × 0.39”

Main crystal size: 0.9 × 0.9 cm = 0.35” × 0.35”