In short, a type locality is the place where a crystal or mineral was first found. For minerals that have been known and used for thousands of years, such as Quartz, Calcite, Emerald, Aquamarine, Ruby and such, there is no recorded type locality, as there is no way to know exactly where these were first discovered.

Type locality recording started officially in 1959, although previous notes and works have been taken into account in giving minerals discovered pre-1959 type localities.

Why are mineral specimens from a Type Locality More Desirable?

 Many collectors like to collect minerals and crystal specimens that are from the original deposit location, as they are tied to the history of the mineral. The minerals are often named after the person who discovered them in that particular location as well, so having a specimen of Wavellite for example, from the same place that William Wavell first discovered Wavellite and subsequently had it named after him, is a special piece.

They are also often harder to come by, as the original deposit may have only been small, or it may have been mined out years ago and closed or built over.

Are Type Locality Specimens the best thing to collect?

It is important to note that Type Locality specimens, although often rarer, are not necessarily the most extraordinary or visually impressive compared to other, later finds. Many original deposits were found a couple of hundred years ago in countries with slightly easier to navigate geography, and over the years more deposits have been discovered in harder to navigate to areas as technology improved. 

For example, the UK holds several type localities, including Ludlamite, Brookite, Wavellite and Vivianite. However, if you were to think of outstanding Ludlamite and Vivianite specimens, you would probably think of the new deposit found in the Amazon; for Wavellite, rather than Devon, Arkansas springs to mind, and when you think of Brookite, Pakistan is surely first to spring to mind rather than Wales?

In summary, if you are after the most beautiful example of a particular crystal, then a Type Locality Specimen is probably not going to be your best bet. However, if you are building a collection and are interested in rarity and geological history as well as crystal aesthetics, then type localities are a wonderful addition to your collection.