REALGAR (AURIPIGMENT) with RATHITE (LENGENBACH)
A very rare and older specimen from the Lengenbach Quarry.
Realgar, also referred to as arsenic blende, ruby sulfur, or ruby of arsenic, is a mineral composed of arsenic sulfide with the chemical formula α-As4S4. This soft and sectile mineral typically forms in monoclinic crystals or appears in granular, compact, or powdery forms, often found alongside the related mineral orpiment (As2S3). Characterized by its orange-red hue, realgar melts at 320 °C and burns with a bluish flame, emitting arsenic and sulfur fumes. It has a Mohs hardness ranging from 1.5 to 2 and a specific gravity of 3.5, with an orange streak. Realgar is trimorphous, existing in forms such as pararealgar and bonazziite.
DO NOT EXPOSE TO LIGHT (DESINTEGRATES)
RATHITE (a complex silver sulfide)
Substitution 2Pb <-> Tl + As. Topa & Kolitsch (2018) revised the general formula to AgxTlyPb16-2(x+y)As16+x+y-zSbzS40 (with 1.6 < x < 2, 0 < y < 3, 0 < z < 3.5).