Jet is a fossilized wood, a form of brown coal.
- Refractive Index : 1.64 to 1.68
- Specific Gravity : 1.3 to 1.4
- Hardness : 2.5 to 4.0
“Black Onyx” is black stained chalcedony.
- Refractive Index : 1.53 to 1.54
- Specific Gravity : 2.58 to 2.64
- Hardness : 6.5
Hold a heated needle to a piece of jet, it will smell like
burning coal, the needle will have no effect on “black onyx”. Jet
will feel warm to the touch, “black onyx” will feel cold to the