| Allargentum | |
| Category: | Sulfide mineral |
| Formula: | Ag1−xSbx |
| Imasymbol: | All[1] |
| Strunz: | 2.AA.30 |
| Dana: | 02.02.01.02 |
| System: | Hexagonal |
| Class: | Dihexagonal dipyramidal (6/mmm) H-M symbol: (6/m 2/m 2/m) |
| Symmetry: | P63/mmc |
| Unit Cell: | a = 2.945, c = 4.77 [Å], Z = 2 |
| Color: | Silver gray |
| Mohs: | 4 |
| Luster: | Metallic |
| Gravity: | 10.0 (meas.), 10.12 (calc.) |
| Diaphaneity: | Opaque |
| References: | [2] [3] |
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 Ag1−xSbx, 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.[2]