# Important iron ores

> Hematite, limonite, magnetite and siderite


## Objectives

- Name the four important iron ores with their chemical names and formulas.
- Match each ore with its colour, properties, iron % and place of deposits.
- Tell the oxide ores (one hydrated, one magnetic) from the carbonate ore.

## 1. Iron ores and extraction of iron




## 2. Which one does the magnet pick?

Predict: the four ores are crushed and mixed. A magnet passes over the pile. Which ore sticks to it?

- The black ore ✓
- The yellow ore
- The blood-red ore

The black ore is magnetite, the ore with magnetic properties, so it sticks to the magnet. Colour alone does not make a rock magnetic: the blood-red and yellow ores do not have magnetic properties.

[ar-EG] الـ ore الأسود هو الـ magnetite، الـ ore اللي عنده خواص مغناطيسية، فهو اللي بيلزق في الـ magnet. واللون لوحده مش بيخلّي الصخرة مغناطيسية: الـ ore الأحمر الدموي والأصفر مالهمش خواص مغناطيسية.
## 3. 1) Hematite

In iron III oxide, iron has oxidation state +3. "Easily reduced" means the oxide easily loses its oxygen to give iron.


## 4. 2) Limonite

Same iron III oxide as hematite, plus water of crystallization: 3 $\ce{H2O}$ for every 2 $\ce{Fe2O3}$. Limonite has no water in it.


## 5. 3) Magnetite

This is the ore the magnet picked out in the hook. Magnetite's formula is $\ce{Fe2O3}$.


## 6. 4) Siderite

Siderite is the odd one out: a **carbonate**, not an oxide. Here iron has oxidation state +2.


## 7. All four together

Iron % range of each ore (book table, p.16) Match each ore to its formula.


## 8. Identify the ore

A geologist finds a black ore in the Eastern Desert. A magnet attracts it. What is its formula?

- $\ce{Fe3O4}$ ✓
- $\ce{FeCO3}$
- $\ce{2Fe2O3.3H2O}$
- $\ce{Fe2O3}$

A black ore from the Eastern Desert that a magnet attracts is magnetite, magnetic iron oxide: $\ce{Fe3O4}$. Hematite ($\ce{Fe2O3}$) is blood red, limonite ($\ce{2Fe2O3.3H2O}$) is yellow and siderite ($\ce{FeCO3}$) is yellowish grey.

[ar-EG] ore أسود من الصحرا الشرقية والـ magnet بيجذبه يبقى الـ magnetite، يعني الـ magnetic iron oxide: $\ce{Fe3O4}$. الـ hematite ($\ce{Fe2O3}$) لونه أحمر دموي، والـ limonite ($\ce{2Fe2O3.3H2O}$) أصفر، والـ siderite ($\ce{FeCO3}$) رمادي مصفرّ.
## 9. Sort the clues

Sort each clue to its ore.


## 10. Summary

Can you explain why siderite is the odd one out? Common exam item: the formula and chemical name of each ore, and which one is magnetic or hydrated.



Chapter: Transition Elements (https://yaani.ai/en/learn/chemistry/chem-s3-en.ch1)
Source: https://yaani.ai/en/lesson/chem-s3-en.lesson-fe.ores