Unfortunately, however, many orpiment localities also contain abundant to trace realgar , sometimes intimately intergrown with the orpiment, leading to overall specimen stability problems.
Orpiment is a lesser mineral associated with realgar and lead sulfosalts in dolomite at Binnental, Valais, Switzerland.
Small amounts of realgar have been reported from a large number of European occurrences, generally related to relatively recent volcanism, limestone or dolomite quarries, or base- and precious-metal deposits.
Even the arsenic mine at Shimen, Hunan Province, is still the source of minor amounts of good realgar , orpiment, and calcite.
The specimen was a classic Lengenbach assemblage: sugary white dolomite matrix, realgar , minor pyrite, and a massive metallic gray sulfosalt that had been labeled as ‘sartorite.’
Other minerals associated with the orpiment crystals are white to colorless barite crystals, lemon-yellow crystalline masses of sulfur, and minor realgar .
Orpiment and realgar are yellow and orange mineral species of arsenic sulphide, used in 16th-century Venetian painting particularly, but at various other times also.
It is an alteration product of realgar , native arsenic, and, less commonly, arsenopyrite.
The next morning we drove west to the famous town of Shimen, the locality for all the superb realgar and orpiment crystals.
A number of relatively minor yet interesting California realgar localities are given by Murdoch and Webb.