Fairburn agate
Lapidary material SiO2
About it
Colourful agate with tight fortification banding and a pitted rind, from the Fairburn area and nearby badlands of southwest South Dakota and northwest Nebraska. South Dakota's state gemstone.
- 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
- red, yellow, orange, brown, black, white
- Transparency
- translucent, opaque
- Cleavage and fracture
- none; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.