1. a bright yellow mineral form of arsenic sulfide, used historically as a pigment and in traditional medicine.
Usage: chemistry; art history

Examples

• Medieval painters used orpiment to create vibrant yellow hues in their manuscripts.
• Orpiment was valued in ancient Egypt for both its color and its supposed medicinal properties.
• The mineral orpiment occurs naturally in volcanic regions and hot springs.
• Due to its arsenic content, orpiment is toxic and is no longer used in modern art supplies.
• Chemists identified orpiment as a compound of arsenic and sulfur in the 19th century.