Oropimente
Oropimente is a mineral with formula As₂S₃, in the Sulfuros group. This specimen comes from Mina Quiruvilca (ASARCO), Santiago de Chuco, La Libertad, Perú and joined the Terrium collection in 2025.
Description
Botryoidal and radial aggregates of orpiment, orange to yellowish, with fibrous texture and silky lustre, coating transparent barite crystals on matrix. Strong colour contrast and pronounced aesthetic character. Here orpiment presents as a poison disguised as gummy sweets.
History of this specimen
Part of my series of orpiments and arsenides within Meritum Persé, one of my personal affiliations in the collection.
About Oropimente
Orpiment is an arsenic sulphide which, although toxic, has historically been used as a pigment.
About the locality
Quiruvilca Mine was a major 20th-century polymetallic operation, noted for its diversity of sulphides and secondary arsenic minerals. It is now closed.
Technical data
- Catalogue No.
- 0184
- Composition
- As₂S₃
- Name
- Oropimente
- Group
- Sulfuros
- Category
- Meritum Persé
- Matrix
- Barita
- Associations
- Barita
- Mine
- Mina Quiruvilca (ASARCO)
- District / Municipality
- Santiago de Chuco
- Province
- La Libertad
- Country
- Perú
- Size (cm)
- 8.5 x 6.7 x 3.5
- Weight
- 187.7 g
- Acquired
- 2025
- Etymology
- From Latin "auripigmentum" (golden pigment). It appealed to artists for its solar sheen, but hid a chemical pitfall: it is incompatible with lead. When mixed with colours such as lead white, its sulphur reacted and blackened the work. Thus many details intended to remain luminous eventually succumbed to a silent chemical struggle between pigments.
- Quality
- Muy buena
- Value trend
- Estable
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