Which one of the following is not an ore of aluminium ?

Options

A. Bauxite
B. Corundum
C. Epsomite
D. Cryolite

Answer

To solve the question "Which one of the following is not an ore of aluminium?", we will analyze each of the given options to determine whether they are ores of aluminium or not.

### Step-by-Step Solution:

1. **Identify the options**: The options provided are:
- Option 1: Bauxite
- Option 2: Corundum
- Option 3: Epsomite
- Option 4: Chiralite

2. **Analyze Option 1: Bauxite**:
- Bauxite is the primary ore of aluminium.
- Chemical formula: Al2O3·2H2O.
- Conclusion: Bauxite is an ore of aluminium.

3. **Analyze Option 2: Corundum**:
- Corundum is another mineral that contains aluminium.
- Chemical formula: Al2O3.
- Conclusion: Corundum is also an ore of aluminium.

4. **Analyze Option 3: Epsomite**:
- Epsomite is not an ore of aluminium.
- Chemical formula: MgSO4·7H2O.
- Conclusion: Epsomite is an ore of magnesium, not aluminium.

5. **Analyze Option 4: Chiralite**:
- Chiralite contains aluminium.
- Chemical formula: Na3AlF6.
- Conclusion: Chiralite is an ore of aluminium.

6. **Final Conclusion**:
- Among the options, Epsomite is the only one that is not an ore of aluminium. Therefore, the correct answer is **Option 3: Epsomite**.

### Summary of Findings:
- Bauxite: Ore of aluminium.
- Corundum: Ore of aluminium.
- Epsomite: Not an ore of aluminium (ore of magnesium).
- Chiralite: Ore of aluminium.

### Answer:
**Epsomite is not an ore of aluminium.**

---