Chief Chemical Elements Which Form Minerals
The larger number of elements play so small a part in the constitution of the earth that they may be neglected by the geologist. The following list includes the elements of which ninety-nine per cent of the earth’s crust, as known to us, is composed, with their relative proportions, as indicated by Clarke’s laborious analyses of a very large number of typical rocks:
| Element | Chemical Symbol | Percentage of Earth’s Crust Which It Forms |
|---|---|---|
| Oxygen | O | 47.02 |
| Silicon | Si | 28.06 |
| Aluminum | Al | 8.16 |
| Iron | Fe | 4.64 |
| Calcium | Ca | 3.50 |
| Magnesium | Mg | 2.62 |
| Sodium | Na | 2.63 |
| Potassium | K | 2.32 |
| Hydrogen | H | 0.17 |
| Carbon | C | 0.12 |
| 99.24 |
The ten elements given above form 99.24 of the earth’s solid crust.