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Topaz:
Topaz has got the chemical formula Al2[F2|SiO4]. So it is an
aluminium silicate. It has got a hardness of 8 and it crystallizes in
the rhombical system. Depending on other substances in a topaz it can
have different colors. Yellow and orange topaz is called
"Imperial Topaz". Topaz is often transparent. We can find
topaz in form of big, long prismatic and short prismatic crystals.
Topaz crystals split very well to their basis surface and so broken
topaz crystals look like they were cut at the bottom. Except sulfuric
acid topaz is a very resistant mineral towards chemical substances.
Already in antiquity topaz was a precious stone. Today topaz is also
a precious stone and jewels are made of topaz. Above all topaz can be
found in Brazil, Pakistan, Russia and in Madgascar.
Data about Topaz
Chemical
formula Al2[F2|SiO4]
Mineral class silicates
Crystal system rhombical
Hardness 8
Density 3.5
g/cm3 to 3.6 g/cm3
Color
colorless, yellow, blue, pink
Line color white
Gloss glass gloss
Break shell
Fissileness perfectly |
