Orpiment

Real mineral · uncommon · As₂S₃

Arsenic trisulfide associated with realgar in volcanic and hydrothermal environments. Its intense yellow colour made it a prized pigment, though its arsenic content made it hazardous to painters. Converts to realgar on heating.

Identity

Formula

As₂S₃

Chemical class

sulfide

Also known as

King's yellow, Yellow arsenic

Crystallography

Crystal system

monoclinic

Habits

foliated, massive, prismatic

Fracture

uneven

Physical properties

Mohs hardness

1.5

Density

3.49 g/cm³

Luster

resinous, pearly

Colors

yellow, orange-yellow, golden yellow

Streak

pale yellow

Transparency

transparent, translucent

Geology

Origins

volcanic, hydrothermal

Host rocks

volcanic deposits, hot spring deposits

Associated minerals

Realgar, Stibnite, Calcite, Barite

Geography

Turkey, China, USA (Nevada), Peru, Romania

Classification

Rarity

uncommon

Gem quality

No

Arcane properties

Affinity

shadow, arcane

Effects

illusion, warding

Planar origin

Material Plane

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