Holley blue agate
Lapidary material SiO2
About it
Lavender to violet-blue chalcedony from around Holley, near Sweet Home, Oregon; its colour is rare among agates.
- 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
- lavender, violet-blue, pale purple
- Transparency
- translucent
- Cleavage and fracture
- none; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.