Plume agate
Lapidary material SiO2
About it
Chalcedony holding feathery, plant-like plumes of iron and manganese minerals. Oregon's Graveyard Point and Priday deposits, West Texas, and Mexico are classic sources.
- Type
- Lapidary material
- Group
- Agate (chalcedony)
- Formula
- SiO2
- Hardness (Mohs)
- 6.5–7
- Specific gravity
- 2.57–2.64
- Streak
- white
- Lustre
- waxy, vitreous (glassy)
- Crystal system
- Trigonal
- Colours
- clear or white with red, yellow, black, or gold plumes
- Transparency
- translucent, opaque
- Cleavage and fracture
- none; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.