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Care

Transparency

Transparent - Opaque

Luster

Vitreous, Greasy

Obsidian

Locales

Hardness

5-5.5
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

Composition

silica

Colours

Black