Realgar is an arsenic sulfide, also known as "ruby sulfur" or "arsenic ruby". It is a soft mineral found in monoclinic crystals or in a granular, compact or powdery form, often in association with another mineral, orpiment (As2S3). It is orange-red in color, melts at 320 ° C and burns with a bluish flame releasing arsenic and sulfur fumes. Its name derives from the Arabic rahj al-ġār (رهج الغار, "dust of the mine"). In the past it was used to make paints, inks and dyes, until it was discovered that it was toxic. The arsenic present in realgar is the source of its toxicity. When its toxicity was discovered in the Middle Ages, the mineral began to be used as a poison for rodents and insects. Orpiment is a monoclinic arsenic sulfide with a yellow-orange color. It has a Mohs hardness of 1-1 / 2 to 2 and is easily ground into powder.
Dimensions
Height (cm): -
Depth (cm): -
Width (cm): 2-4
Weight (g): 5-20
Property
Chemical Formula: As4S4 or AsS
Mohs scale: 1.5–2
Relative density: 3.56
Crystalline System: Monoclinic