Ore genesis and loses its metal carrying capacity. Ore deposits rarely fit neatly into the categories in which geologists wish to place them. Many may be formed by one or more of the basic genesis processes above, creating ambiguous classifications and much argument and conjecture. Often ore deposits are classified after examples of their type, for instance Broken Hill type lead-zinc-silver deposits or Carlin–type gold deposits. Classification of hydrothermal ore deposits is also achieved by classifying according to the temperature of formation, which roughly also correlates with particular mineralising fluids, mineral associations and structural styles. This scheme, proposed by Waldemar Lindgren (1933)
Heavy mineral sands ore deposits deposit is usually low. Within the 21st century, the lowest cut-off grades of heavy minerals, as a total heavy mineral (THM) concentrate from the bulk sand, in most ore deposits of this type is around 1% heavy minerals, although several are higher grade. Of this total heavy mineral concentrate (THM), the components are typically Generally, as zircon is the most valuable component and a critical ore component, high-zircon sands are the most valuable. Thereafter, rutile, leucoxene and then ilmenite in terms of value given to the ore. As a generality, typically the valuable components of the THM concentrate rarely exceed