Minerals are generally found in "ores", which is actually an accumulation of any mineral mixed with other elements. To obtain a pure mineral, the it has to be separated from its ore.
This process of separating the mineral from its ore is called smelting
Minerals generally occur in many forms, they are:
1. Veins and Lodes
Minerals generally occur in the cracks, crevices, faults and joints of the igneous and metamorphic rocks. Smaller occurrence of such type is called a vein and a larger occurrence is called a lode.
Minerals like tin, copper, zinc, and lead etc. are found in veins and lodes
2. Beds or Layers
The minerals which are formed as a result of deposition, accumulation and concentration generally occur in horizontal layers.
Minerals such as coal, gypsum, potash salt and sodium salts are formed in such modes.
3. Residual mass of weathered particles
When the decomposed rocks are washed away by water, the soluble constituents are removed leaving a mass containing ores. Such occurrences are called residual mass. Bauxite occurs in such a mode.
4. Alluvial deposits or Placer deposits
These are the deposits found in the sands of valley floor and at the foot hill. These deposits consist of the minerals which cannot be corroded by water.
Gold, silver,tin,platinum are some of the minerals found in such deposits.