What is a type locality?
The locality a species was first described from, and where its type material was collected. Not the best locality, the only one, or a claim about quality.
A type locality is the place a mineral species was first found and described from, and where the type material in a museum was collected. It is not a quality claim: vivianite's type locality is in Cornwall, but the Handbook of Mineralogy records huge crystals from Cameroon, against a species maximum of 1.3 m.
In short
- It is a fact about a scientific paper, not about a specimen. The type locality is where the material used in the original description came from. Everything people infer beyond that — quality, rarity, desirability — is inference.
- The type locality is often not the best locality. Vivianite's is Cornish, but the finest crystals come from Bolivia and Cameroon. Dioptase was described from Kazakhstan; the specimens people chase are Namibian and Congolese.
- Type material is a physical thing in a named institution, with a catalogue number. Mimetite's is at the Mining Academy in Freiberg, number 20225; atacamite's is Harvard 110816. That number is checkable.
- “Type locality specimen” on a label usually means only “from the type locality” — not that the specimen is part of the type material. Those two claims differ by an enormous margin and the phrasing blurs them.
- Some type localities are lost or were never precisely recorded. Atacamite is named for the Atacama Desert and the Handbook of Mineralogy notes the original occurrence was never precisely located.
| Species | Type locality | Where the best material comes from |
|---|---|---|
| Vivianite | St Agnes, Cornwall | Bolivia and Cameroon — not Cornwall |
| Mendipite | The Mendip Hills, Somerset | The Mendips. Type locality and best locality coincide here |
| Leadhillite | Leadhills, Scotland | Leadhills, and the Mammoth-St Anthony mine in Arizona |
| Pseudomalachite | Virneberg, Rheinbreitbach, Germany | Widely distributed; Cornwall and the Congo among the notable sources |
| Atacamite | Atacama Desert, Chile — never precisely located | Chile, Australia and Namibia |
| Dioptase | Altyn-Tyube, Kazakhstan | Tsumeb in Namibia and Mindouli in the Congo |
| Adamite | Chañarcillo, Chile | The Ojuela mine, Mapimí, Mexico |
The precise definition, and the two things it is not
When a new mineral species is described, the description rests on actual material: a specimen or set of specimens that were analysed, measured and used to establish that this is something distinct from everything already known. That material is the type material, it is deposited in a named museum or institution with a catalogue number, and the place it was collected from is the type locality.
The process is administered by the IMA Commission on New Minerals, Nomenclature and Classification, which approves new species and their names. Approval fixes the type locality; it is settled at that moment and does not change because a better occurrence turns up later.
It is not a quality claim. The type locality is wherever the person who first noticed the mineral happened to be looking, which is usually a function of nineteenth-century mining activity and the location of European mineralogists rather than of where the species occurs best.
It is not an exclusivity claim. A type locality is the first recorded locality, not the only one. Most species are known from many, some from hundreds.
The single most useful reframing: a type locality tells you about the history of science, not about the specimen in front of you. That is a real and interesting thing to know. It is simply not the thing most labels imply.
Type locality, co-type locality, type material — and the phrase that misleads
Four related terms get used loosely, and the differences carry real weight.
Type locality: where the originally described material came from. Co-type locality: where an original description drew on material from more than one place, all of them count. Type material: the actual specimens used, in an institution, catalogued — holotype where a single specimen defines the species, cotypes or syntypes where several do, neotype where the original was lost and a replacement was formally designated. Topotype: a specimen from the type locality that is not part of the type material.
The phrase that causes trouble is “type locality specimen”. Read literally it means a specimen from the type locality, which is what it almost always is and which is a modest claim: there may be tens of thousands of them. Read carelessly it sounds like a specimen that is part of the type material, which would be an extraordinary claim, because type material sits in museums and does not circulate.
The test: if a specimen were genuinely part of the type material, it would have an institutional catalogue number and a deaccession history, and the seller would lead with both. Absent those, read “type locality” as a geographical statement and price it as one.
Type material numbers are checkable and worth knowing as examples of what real ones look like: the Handbook of Mineralogy records mimetite's type material at the Mining Academy in Freiberg, Germany, catalogue 20225, and atacamite's at Harvard, 110816. Our page on what the abbreviations on a mineral label mean covers how to weigh claims of this kind generally.
Why the type locality is so often not the good one
The pattern is systematic once you see it, and it is a straightforwardly historical effect.
Species were described where mineralogists were, and mineralogists were in Europe, working on material from European mines and from the colonial mining ventures that shipped specimens back. A mineral that occurs superbly in Namibia and passably in Cornwall was described from Cornwall, because that is where somebody was looking in 1817.
Vivianite makes the point neatly. It is named for John Henry Vivian (1785–1855) of Truro, who discovered the species, and its type locality is Cornish, at St Agnes. Cornish vivianite is historically important and mineralogically genuine. It is not what anyone means by a fine vivianite — the Handbook of Mineralogy records huge crystals from Anloua in Cameroon and exceptional examples from Bolivia, and gives a species maximum of 1.3 m. Dioptase is the same story: described from Altyn-Tyube in Kazakhstan, collected today from Tsumeb and Mindouli. Adamite was described from Chañarcillo in Chile and is collected from the Ojuela mine at Mapimí.
Sometimes they coincide. Mendipite was described from the Mendip Hills and the Mendips remain the locality — because the assemblage there is genuinely unusual and barely occurs elsewhere. Leadhillite comes from the Susanna mine at Leadhills, and Leadhills material remains fully competitive.
The practical consequence for a collector: when a label leads with “type locality” rather than with the mine, ask why. Sometimes it is because the type locality is the interesting fact. Sometimes it is because it is the most impressive-sounding fact available. Our page on reading a listing covers the general form of that question.
When a type locality genuinely does add value
Having spent three sections deflating the term, it is only fair to say where it carries real weight, because there are cases.
When the type locality no longer exists or is inaccessible. A species described from a mine that closed in 1880 and has since been built over means all extant material is historic, finite and not being replaced. Here the type locality is doing real work, though what is actually doing it is scarcity plus history.
When the specimen is old enough to be near-contemporary with the description. A nineteenth-century labelled specimen from a type locality is a documented object with a place in the history of the species, and that is a genuine and checkable form of interest — see buying old collection material.
When you are building a systematic or thematic collection. A type-locality suite is a coherent collecting project with a defined scope, and within it the attribute is the whole point rather than a marketing line.
When the type locality is also a distinctive one. Where the type locality produces material with recognisable character — a particular habit, colour or association — the label is telling you about the specimen and not only about a paper.
What none of these amount to is a general premium. A poor specimen from a type locality is a poor specimen. The rule: type locality is a reason to want a particular specimen, never a reason to accept a worse one. If type-locality material is the collection you are assembling, that is exactly the kind of defined brief worth putting on a wanted list, because it turns a vague preference into something findable — and it is much easier to check a claim before a specimen is bought than to unpick it afterwards.