Sweetwater agate
Lapidary material SiO2
About it
Small, pebble-sized grey agates with black dendrites from the Sweetwater River area of central Wyoming. Easy to spot at night with a UV lamp, since they glow green.
- 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
- grey, clear, with black dendrites
- Transparency
- translucent
- Cleavage and fracture
- none; conchoidal fracture
- Under UV light
- bright yellow-green under UV
Typical values: real specimens vary. For more, see mindat.org.