The correct option is Metallic minerals.
Explanation
The mode of occurrence of minerals is strictly determined by the geological structure and the type of rocks involved. Minerals are generally classified based on the rock formations-igneous, metamorphic, or sedimentary-in which they are found.
Detailed Analysis
- Igneous and Metamorphic Rocks: In these rock types, minerals primarily occur in cracks, crevices, faults, or joints. Smaller occurrences are known as veins, while larger ones are called lodes. These formations are the primary source of metallic minerals. Examples include tin, copper, zinc, lead, iron ore, manganese, and nickel.
- Sedimentary Rocks: In these formations, minerals occur in beds or layers due to deposition, accumulation, and concentration in horizontal strata. This category typically contains non-metallic minerals (such as limestone and phosphate) and energy resources like fossil fuels (coal and petroleum).
- Alluvial Deposits: These are specific accumulations known as placer deposits found in the sands of valley floors and the base of hills, containing minerals like gold and platinum that are not corroded by water.
Key Takeaway: Metallic minerals are characteristically associated with igneous and metamorphic rock formations, whereas non-metallic minerals and fossil fuels are predominantly found in sedimentary rocks.