Ellensburg blue
Lapidary material SiO2
Also called Ellensburg blue agate
About it
Rare cornflower-blue agate found only in Kittitas County around Ellensburg, Washington, as small nodules and seams. Among the most valued North American 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
- cornflower blue, sky blue
- Transparency
- translucent
- Cleavage and fracture
- none; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.