Fire agate
Lapidary material SiO2
About it
Brown chalcedony with thin layers of iron oxide that give rainbow "fire" when carefully ground down by hand. Found in Arizona, California, and the Mexican states of Aguascalientes and Chihuahua.
- 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
- brown with iridescent red, orange, green, gold, and blue
- Transparency
- translucent, opaque
- Cleavage and fracture
- none; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.