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

Options

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

Answer

To determine which of the given options is not an ore of aluminium, we will analyze each option one by one.

### Step 1: Identify the ores of aluminium
1. **Bauxite**:
- Bauxite is a primary ore of aluminium.
- Chemical formula: Al₂O₃·2H₂O (Aluminium oxide with water).

2. **Corundum**:
- Corundum is also an ore of aluminium.
- Chemical formula: Al₂O₃ (Aluminium oxide).

3. **Epsomite**:
- Epsomite is not an ore of aluminium.
- Chemical formula: MgSO₄·7H₂O (Magnesium sulfate with water).

4. **Cryolite**:
- Cryolite is an ore of aluminium.
- Chemical formula: Na₃AlF₆ (Sodium aluminium fluoride).

### Step 2: Conclusion
From the analysis, we can conclude that:
- Bauxite, Corundum, and Cryolite are ores of aluminium.
- Epsomite is not an ore of aluminium.

Thus, the correct answer is **Epsomite**.

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

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