Chemical Description: Purple PYROCLASTIC porous rock (rocks formed by the cementation of volcanic ejecta).
• Lightfastness - 8
• Alkali resistance: 5
• Lime resistance: 5
• Acid resistance: 5
• Suitable for acrylic, fresco, ceramic, oil, tempera, watercolor/gouache, silicate binder, cement/plaster
• Purple color
• Powder
• High hiding power.