A mineral can be termed economic or
uneconomic depending on its industrial use. The mineral quartz is economic as
silica sand used in glass or optical industry. The same mineral is uneconomic
when it hosts gold as auriferous quartz vein or occurs as a constituent of
rocks hosting copper, zinc and iron ore. It is then processed and discarded as gangue, tailing or waste. The ore deposits
are generally composed of a main product,
one or more by-products and trace
copper-gold, chromium-nickel platinumpalladium.
Sometimes a single mineral forms the valuable deposit such as calcite in marble. The same
mineral can be
designated as metallic or industrial depending on
its use. Bauxite ore is “metallic” when aluminum is produced and “industrial” when used directly for refractory
bricks and abrasives.
An ore deposit can be composed of metallic and nonmetallic minerals, mined together and
processed to produce separate
products. An example can be BouJabeur deposit,
Tunisia, containing galena and sphaleritealong
with fluorite and barite.
The economic minerals occur in various
forms such as native elements
to compounds of oxide, carbonate, silicate,
sulfide, sulfate, sulfosalts, phosphate etc.