a = 9.909 Å, b = 9.655 Å, c = 8.502 Å; β = 97.20°; Z = 16
Identification
Colour
Bright yellow when powdery, to yellow-orange and orange-brown when granular
Crystal habit
Fine powder to granular
Fracture
Uneven
Tenacity
Brittle
Mohs scale hardness
1 – 1.5
Lustre
Vitreous to resinous
Streak
Bright yellow
Diaphaneity
Translucent
Specific gravity
3.52
Optical properties
Biaxial (?)
Birefringence
2.02
Pleochroism
High: x = orange yellow, y = bright yellow, z = orange red
References
[2][3][4][5]
Pararealgar is an arsenic sulfide mineral with the chemical formula As4S4,[3] also represented as AsS.[5] It forms gradually from realgar under exposure to light. Its name derives from the fact that its elemental composition is identical to realgar, As4S4. It is soft with a Mohs hardness of 1 - 1.5, is yellow orange in colour, and its monoclinic prismatic crystals are very brittle, easily crumbling to powder.
It is one of the sulfides of arsenic and is one of two isomers of As4S4. It forms upon exposure of the symmetrical isomer to light. Its name derives from the fact that its elemental composition is identical to realgar, As4S4.
Pararealgar is an arsenic sulfide mineral with the chemical formula As4S4, also represented as AsS. It forms gradually from realgar under exposure to...
gravity of 3.5. Its streak is orange colored. It is trimorphous with pararealgar and bonazziite. Its name comes from the Arabic rahj al-ġār (رهج الغار...
Tetraarsenic tetrasulfide, As4S4 (2 isomers): the mineral realgar the mineral pararealgar Tetraarsenic trisulfide, As4S3, the mineral α- or β- dimorphite This...