when does a mineral become a mineral resources
Mineral resource classification A 'Mineral Resource' is a concentration or occurrence of material of intrinsic economic interest in or on the earth's crust in such form, quality and quantity that there are reasonable prospects for eventual economic extraction. Mineral Resources are further sub-divided, in order of increasing geological confidence, into inferred, Indicated and measured Categories.
Evaporite Marine evaporites tend to have thicker deposits and are usually the focus of more extensive research.[2] They also have a system of evaporation. When scientists evaporate ocean water in a laboratory, the minerals are deposited in a defined order that was first demonstrated by Usiglio in 1884.[2] The first phase of the experiment begins when about 50% of the original water depth remains. At this point, minor carbonates begin to form.[2] The next phase in the sequence comes when the experiment is left with about 20% of its original level. At this point, the mineral gypsum begins to form, which is then followed by halite at 10%,[2] excluding carbonate minerals that tend not to be evaporites. The most common minerals that are generally considered to be the most representative of marine evaporites are calcite, gypsum and anhydrite, halite, sylvite, carnallite, langbeinite, polyhalite, and kainite. Kieserite (MgSO4) may also be included, which often will make up less than four percent of the overall content.[2] However, there are approximately 80 different minerals that have been reported found in evaporite deposits (Stewart,1963;Warren,1999), though only about a dozen are common enough to be considered important rock formers.[2]