1.2.7: Anthropogenic Minerals

1.26 Simonkolleite, a hydrated zinc chloride

Crystalline materials that derive from human-produced materials or actions, but meet the definition of a mineral in other ways, are sometimes considered minerals – but generally not. For example, the rust that forms on our cars is not considered a mineral (although the mineral goethite has nearly the same composition and properties). And simonkolleite, a hydrated zinc chloride mineral (Figure 1.26), has been found in some smelter slag but nowhere else.

In 2017 Robert Hazen identified 208 distinct mineral species – all approved by the IMA – that only exist because of human activities and materials. There are no natural analogs. Most of the 208 derive from mining activities – perhaps as scaling on mine walls, as new compounds created in mine dumps, or as precipitates at high temperature in smelters or at low temperature from mine waters. A few developed by alteration of human materials, for example due to weathering of ancient lead or bronze artifacts. In 1998, the IMA decided that, going forward, no substances derived from human-created materials or activities could be called a mineral. But, they have made a few special exceptions since then and have “grandfathered in” many previously identified mineral species.

1.27 Martyite, an anthropogenic mineral containing zinc and vanadium

The photo seen in Figure 1.27 shows red-orange martyite, a zinc-vanadium hydrated mineral that precipitated from mine waters flowing from the Blue Cap Mine near Moab, Utah. This mineral would not exist if it were not for mine waste waters flowing through tailings piles. It was officially approved as a mineral in 2007 and retains that honor today.