| Mineral class | Sulphides : Antimonite bismuthinite orpiment group |
| Chemical formula | As4S4 |
| Crystal system | Monoclinic. |
| Habitus | Crystals prismatic striated with diamond cross section, terminated by a wedge-like dome. Often as grains or crusts. |
| Cleavage | [010] good, subconchoidal fracture. |
| Hardness | 1.5 - 2 |
| Density | 3.5 - 3.6 |
| Color | Bright red, dark red or orange red, transparent to translucent. |
| Streak | Yellow to orange. |
| Luster | Submetallic. |
| Description | |
| Occurance | Usually found in hot springs and around volcanic vents. Also in hydrothermal veins. |
| Associates | |
| Notes |
The name comes from the Arabic, rahj al ghar, "powder of the mine". Realgar is sensitive to light and air. When exposed it starts to deteriorate into a yellow powder, pararealgar. Realgar should be stored air tight and in a dark place. Realgar shows some pleochroism between orange red to dark red. |
| Localities | A rare mineral in Sweden
|
| To sulphides index. |
Mineral group index. |
Main index. |
If you have some questions, suggestions or comments you are welcome to write me a line or two.