Binghamite
Lapidary material SiO2
Also called Silkstone
About it
Chatoyant quartz packed with goethite and hematite fibres, like a red-gold tiger's eye, from the Cuyuna iron range of central Minnesota. Named for its finder, William Bingham.
- Type
- Lapidary material
- Group
- Quartz with goethite
- Formula
- SiO2
- Hardness (Mohs)
- 6.5–7
- Streak
- white
- Lustre
- silky, vitreous (glassy)
- Crystal system
- Trigonal
- Colours
- golden yellow, red, brown
- Transparency
- opaque
- Cleavage and fracture
- none; uneven fracture
Typical values: real specimens vary. For more, see mindat.org.