|North America||Mammoth Mine, Tintic District, Juab County, Utah||3 ½" x 2 ½" x 2 ½"|
Specimen #30 contains two minerals, one of which is linarite, PbCu(SO4)(OH)2. This is the same mineral, but from a different locality. The names of minerals are sometimes taken from the places where they were first found, which is the case here. Linares, Spain, is where linarite was first identified. Nevertheless, whenever a mineral of the same composition and same crystal structure is found anywhere, it is linarite. Were it not so, we would end up with a multitude of names for the same mineral, found in different places by different people. There are about 5,000 known minerals, with up to dozens more being discovered each year, so avoiding redundant names is important.
But what happens if two specimens found at different places and times are given names without recognizing that they are the same mineral? This can happen when the chemical analyses don't match well, for example. Eventually, someone does a scientific study that involves one or both minerals, resulting in the recognition of the problem. The problem is resolved by the International Mineralogical Association (IMA), which has a commission that concerns itself with mineral names. That commission will gather the necessary information and decide which name has precedence.
An aside: Many mineralogists and geologists knew one of the more common of earth's minerals as idocrase for many years. Then the IMA commission found that another name - vesuvianite - had precedence by 4 years, 1795 versus 1799. So they abruptly changed the official name to vesuvianite, which took some getting used to. Several other names of common minerals have met the same fate .