Which one of the following minerals has isolated (SiO$_4$)$^{4-}$ tetrahedra linked by divalent cations in octahedral coordination?
Step 1: Understanding the question.
The question asks about a mineral that has isolated tetrahedra of SiO$_4$ linked by divalent cations in octahedral coordination. This is characteristic of the mineral olivine.
Step 2: Analyzing the options.
(A) Muscovite: Muscovite is a type of mica, with a different structure from olivine.
(B) Quartz: Quartz consists of SiO$_2$ where the tetrahedra are not isolated, but form a continuous chain or framework.
(C) Beryl: Beryl is a silicate mineral with a hexagonal crystal structure, not isolated tetrahedra.
(D) Olivine: This is the correct answer. Olivine has isolated SiO$_4$ tetrahedra linked by divalent cations in octahedral coordination.
Step 3: Conclusion.
The correct answer is (D) Olivine because it matches the description of the mineral with isolated SiO$_4$ tetrahedra.
| Group I | Group II |
| P. Sillimanite | 1. First order |
| Q. Quartz | 2. Second order |
| R. Muscovite | 3. Greater than third order |
| S. Calcite | 4. Third order variegated |
| Group I | Group II |
| P. Bababudan Group | 1. Eastern Dharwar |
| Q. Banded Gneissic Complex-I | 2. Western Dharwar |
| R. Bonai Granite | 3. Aravalli |
| S. Kolar Group | 4. Singhbhum |