Science Education
The 10 Most Abundant Compounds in the Earth's Crust
Source: Exploring Chemical Elements and their Compounds; David L. Heiserman, 1992
| Compound | Formula | Abundance percent by weight | Abundance parts per million by weight |
| Silicon dioxide | SiO2 | 42.86% | 428,600 |
| Magnesium oxide | MgO | 35.07% | 350,700 |
| Ferrous oxide | FeO | 8.97% | 89,700 |
| Aluminum oxide | Al2O3 | 6.99% | 69,900 |
| Calcium oxide | CaO | 4.37% | 43,700 |
| Sodium oxide | Na2O | 0.45% | 4,500 |
| Ferric oxide | Fe2O3 | 0.36% | 3,600 |
| Titanium dioxide | TiO2 | 0.33% | 3,300 |
| Chromic oxide | Cr2O3 | 0.18% | 1,800 |
| Manganese dioxide | MnO2 | 0.14% | 1,400 |
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