Sedimentary Rocks
crystal structures
These rocks shown here don't contain silicon!
Calcite
CaCO3. It has the same chemical composition as chalk. It is important in optics. It is birefringent.
Dolomite
(Ca,Mg)CO3
It is typical of the Italian Alps.
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Siderite
FeCO3 - a carbonate mineral.
The structure is similar to that of calcite, although Fe is smaller than Ca. It is an important Fe ore. Possibly gave origin to the word siderurgy, as the industry of obtaining Fe metal from rocks.
