Iron is naturally made through geological processes that occurred billions of years ago. Nearly all of Earth's iron originates from ore deposits in rocks formed more than 1.8 billion years ago. These deposits formed in a very specific way:
The Natural Formation of Iron
The Role of Early Life
- Early organisms capable of photosynthesis played a critical role.
- These organisms released oxygen into the oceans.
Chemical Reaction in the Oceans
- The released oxygen combined with dissolved iron present in the oceans.
- This chemical reaction led to the production of iron oxides, specifically haematite or magnetite.
Formation of Ore Deposits
- Over vast geological timescales, these iron oxides precipitated out of the water.
- They accumulated on the seabed.
- Eventually, these deposits hardened and transformed into the iron ore deposits we find today within rocks.
| Step | Description | Key Players | Outcome |
|---|---|---|---|
| 1 | Photosynthetic organisms release oxygen. | Early life forms | Increased oxygen levels in the oceans. |
| 2 | Oxygen reacts with dissolved iron. | Oxygen, dissolved iron | Formation of iron oxides (haematite/magnetite). |
| 3 | Iron oxides precipitate and accumulate. | Iron oxides, water, sediment | Creation of iron ore deposits in rocks. |
Essentially, the iron we use today is a direct result of ancient life altering the chemistry of the Earth's oceans. Without those early photosynthetic organisms, the vast iron ore deposits we rely on might not exist.
