Find out where these minerals are found?
Minerals are found in various forms. In igneous and metamorphic rocks, minerals occur in cracks, crevices, faults or joints. The smaller occurrences are called veins and the larger ones are called lodes. Major metallic minerals like tin, copper, zinc and lead are obtained from these.
In sedimentary rocks, minerals occur in beds or layers. Coal, iron ore, gypsum, potash salt and sodium salt are found here. Certain minerals also occur as alluvial deposits in sands of valley floors and base of hills, called placer deposits. Gold, silver, tin and platinum are found in such deposits.
Additionally, ocean waters contain minerals like common salt, magnesium and bromine, while ocean beds are rich in manganese nodules.
Explanation
The textbook context clearly outlines four main modes of mineral occurrence: (i) in igneous and metamorphic rocks as veins and lodes, (ii) in sedimentary rocks as beds or layers, (iii) as placer deposits in alluvial sands, and (iv) in ocean waters and ocean beds. A 2-mark answer requires covering these key locations with proper terminology.