Kentucky agate

Lapidary material SiO2

About it

Colourful banded agate nodules found in creek beds of eastern Kentucky, especially Estill and Jackson counties. Kentucky's state rock.

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, black, white, grey
Transparency
translucent, opaque
Cleavage and fracture
none; conchoidal fracture

Typical values: real specimens vary. For more, see mindat.org.