mineral composition, and cleavage

Major mineral composition groups:
silicates: Si+O+more metals
carbonates: CO3+one or more metals
oxides: O+one or more metals
sulfates: SO4+one or more metals
sulfides: S+one or more metals
haldes: Cl or F+a metal



Ceavage:

If the minerals displays a plane, flat, even or smooth face in a wrecked or broken surface, it has cleavage.

The cleavage can be in one, two, three of four directions.

• In one direction: Mica minerals are the best examples, crystals appear in thin sheets, and they have only one direction or plane. These crystals resemble a piece of scotch tape, if colorless Muscovite, if it is black Biotite.



• Inb two directions: a perfect crystal of Gypsum will display two different parallel lines.



• In three directions: all the cubic crystals will show three different and parallel planes, the most common minerals with cleavage in three directions are: Halite, Galena and Calcite.