HESSITE

    Class : Sulfides and sulfosalts
    Subclass : Tellurides
    Crystal system : Monoclinic
    Chemistry : Ag2Te
    Rarity : Rare

Hessite is a rare hydrothermal mineral from epithermal gold-bearing veins that accompanies native gold and other tellurides (petzite, sylvanite, coloradoite). It was named in honor of the Swiss chemist Germain Henri Hess who studied the mineral. Hessite is gray in color with a strong metallic luster, it is usually massive, compact to finely granulated, rarely in crystals ; these are often very deformed, elongated prismatic to twisted pseudocubic, with rounded faces. It is an ore of tellurium and silver.

Main photo : Hessite and quartz from Botesti, Zlatna, Romania © Rock Currier

9 cm hessite and quartz from Botesti, Zlatna, Romania © Kelly Nash
Hessite of Botesti, Zlatna, Romania © Allan Young
Hessite and native gold from Botesti, Zlatna, Romania © Vandall Thomas King
Hessite and native gold from Botesti, Zlatna, Romania © Italo Campostrini

Hessite in the World

The most beautiful known hessite crystals are 6 cm elongated prisms from the Botesti mine near Zlatna (Romania).

Hessite in France

In France, hessite is reported at the Château-Lambert silver mine (Haute-Saône) as well as at the Chizeuil mine (Saône-et-Loire). It is also found at the Clausis mine and the Clochettes mine (Hautes-Alpes).

Twinning

Lamellar twins are visible in polished sections.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 2 to 3
Density : 8.24 to 8.45
Fracture : Undeterminated
Streak : Black

TP : Opaque
RI : -
Birefringence : -
Optical character : -
Pleochroism : None
Fluorescence : None

Solubility : -

Magnetism : NoneRadioactivity : None