Germany DDR
0.06 - 0.07$
price on 06.08.2023
Proustite is a sulfosalt mineral consisting of silver sulfarsenide, Ag3AsS3, known also as light red silver or ruby silver ore, and an important source of the metal.
| Country: | Germany DDR |
| Type: | Postage stamps |
| Series: | 200th Anniversary of the Mining Academy in Freiberg |
| Nominal: | 20 Pf. |
| Year: | 1965 |
| Size: | 43 x 26 mm |
| Perforation: | comb 13 x 12½ |
| Mintage: | 5,000,000 |
200th Anniversary of the Mining Academy in Freiberg
 Hearth Furnace 0.06$ |  Ore Extraction 0.18$ |  Proustite 0.06$ |  Sulfur 0.06$ |