Natural Orpiment Crystal Specimen 32g

A rough orpiment mass measuring 50x27x20mm, with most of its surface carrying a powdery ochre-orange crust. Where that crust has broken away, rows of bladed golden-yellow crystals lie in parallel across the upper face and down the left side, showing the resinous, almost metallic luster of fresh orpiment against the matte orange around them. Scarlet-red patches of realgar run between the blades and through the middle of the piece, and a small dark grey area sits toward one end. The specimen is opaque throughout, with the layered, platy structure clearly visible wherever it has parted.

Orpiment is an arsenic sulfide that forms at low temperatures, in hydrothermal veins and around hot springs, most often with realgar as its companion. Its name goes back to the Latin auripigmentum, gold pigment, from the centuries when it was ground down into one of the few bright yellow paints available to painters and manuscript illuminators. Chinese deposits have supplied much of the orpiment seen in collections over the past few decades. This piece is untreated, and at 1.5 to 2 on the Mohs scale it is soft enough to mark with a fingernail. One caution: orpiment contains arsenic. Wash your hands after handling it, keep it away from children, and never place it in water or near food.

Natural orpiment mineral specimen from China, sold as shown.