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Care

Transparency

Translucent - Opaque

Luster

Vitreous, Greasy

Petrified Wood

Locales

Hardness

7
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
10
10

Treatment

Interesting Fact

Chemical Formula

SiO2 or CaCO3

Composition

silicon dioxide or calcium carbonate

Colours

Brown
Red
Yellow
Green