hessite

Hessite is a mineral species in the telluride group with the chemical formula Ag2Te. It is the natural silver telluride and is commonly found in hydrothermal telluride ore veins. It often occurs with other tellurides such as sylvanite (Ag,Au)2Te4, calaverite (AuTe2), and petzite (Ag3AuTe2), as well as with native gold and silver.

Hessite crystallizes in the tetragonal system and forms metallic, often prismatic or tabular crystals, as well as granular to massive aggregates. It has a steel-gray to black color, a bright metallic luster, and is opaque. The Mohs hardness is about 2–3, and the specific gravity is high, typically around 7 or more.

Hessite is reported in hydrothermal ore deposits globally, including major mining districts in Siberia, North America, and Australia. It occurs as veins and disseminated grains within telluride assemblages and is commonly found with other tellurides such as calaverite, sylvanite, and petzite.

The name Hessite commemorates a contributor to telluride mineralogy.