Primary minerals

Secondary minerals

1. They are formed in the cooling and solidification of molten mass.

1. They are formed by weathering of primary minerals.

2. They are mostly concentrated in coarse fraction of soil.

2. They are dominant in majority of soil clays.

3. Physical and chemical properties of soil are not controlled by primary minerals.

3. Physical and chemical properties of soil are controlled by secondary minerals.

4. They are not capable of being synthesized.

4. They are capable of being synthesized.

5. Example: Quartz, feldspar, micas, amphiboles etc.

5. Example: Limonite, calcite, dolomite etc.