| 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. |
