What is "allargentum"

n. (context mineral English) A hexagonal-dihexagonal dipyramidal silver gray mineral containing antimony and silver.

Allargentum is a mineral from the class of antimonides, superclass of sulfides and sulfosalts (sometimes ascribed to the natural elements and alloys class), with formula written as AgSb, where x = 0.09–0.16. This moderately rare mineral is found in silver ores and is therefore named from the Greek ἄλλος (allos, "another") and the Latin argentum ("silver"). Its Vickers hardness is 172–203.