Onyx

Frae Wikipedia
Jump to navigation Jump to search
Onyx
A photograph shawin a slice through a stane wi the face displayin alternating bands o bricht reid, bricht white an tan
A slice o sardonyx (width = 2.5 cm)
General
CategoryOxide mineral
Formula
(repeatin unit)
Silica (silicon dioxide, SiO2)
Creestal seestemTrigonal, Monoclinic
Identification
Formula mass60 g / mol
ColourVarious
CleavageAbsent
FracturUneven, conchoidal
Mohs scale haurdness6–7
SkinkleVitreous, silky
StreakWhite
DiaphaneityTranslucent
Speceefic gravity2.65–2.667
Onyx

Onyx is a bandit variety o chalcedony. The colours o its bands range frae white tae almaist every colour (save some shades, sic as purpie or blue). Commonly, specimens o onyx contain bands o black an/or white.