Which of the following does not contain aluminium?

Options

A. Cryolite
B. Fluorspar
C. Feldspar
D. Mica

Answer

To determine which of the following substances does not contain aluminum, we will analyze each option based on their chemical composition:

1. **Cryolite**:
- Chemical formula: Na3AlF6
- Contains aluminum (Al).

2. **Fluorspar**:
- Chemical formula: CaF2
- Does not contain aluminum.

3. **Feldspar**:
- Chemical formula: KAlSi3O8 (for potassium feldspar)
- Contains aluminum (Al).

4. **Mica**:
- Chemical formula: KAl3Si3O10(OH)2
- Contains aluminum (Al).

After analyzing the chemical compositions, we find that:

- Cryolite contains aluminum.
- Feldspar contains aluminum.
- Mica contains aluminum.
- Fluorspar does not contain aluminum.

Thus, the correct answer is **Fluorspar (CaF2)**, as it is the only option that does not contain aluminum.