Eugenite is a rare silver-mercury mineral. It crystallizes in the orthorhombic crystal system.
Its occurrence was first confirmed in the Sieroszowice copper mine, Lubin-Sieroszowice district, Poland.
The mineral is named in honor of Eugen Friedrich Stumpfl (27 November 1931, Munich, Germany - 12 July 2004, Innsbruck, Austria), professor of mineralogy, Mining Institute, Leoben (Austria), for his studies of noble metal compounds.
It has a silver white color. And it is metallic and isometric.
It is mostly found in cuprite and in low-grade copper sulfide ores in shale and carbonate rocks.