Question

Which mineral(s) among the following represent(s) AB₂O₄ composition?

• A. Spinel
• B. Magnetite
• C. Chromite
• D. Ilmenite

Hint:

Spinel group formula: AB\textsubscript{2}O\textsubscript{4}, with A = divalent and B = trivalent cation.

Answer 1

The Correct Option is A, B, C

Step 1: Understanding spinel group formula.
Minerals with the general formula AB₂O₄ have a cubic (isometric) spinel structure. In this structure, ‘A’ is a divalent cation and ‘B’ is a trivalent cation.
Step 2: Classification.
- Spinel: MgAl₂O₄ → AB₂O₄ type.
- Magnetite: Fe²⁺Fe₂³⁺O₄ → AB₂O₄ type (inverse spinel).
- Chromite: FeCr₂O₄ → AB₂O₄ type.
- Ilmenite: FeTiO₃ → Not spinel type (belongs to rhombohedral structure).
Step 3: Conclusion.
Hence, the minerals Spinel, Magnetite, and Chromite have AB₂O₄ composition.