(520) 322-5773

tgms@tgms.org

Tungsten Minerals

By Bill Shelton

Few elements have alternate monikers but tungsten – “heavy stone” – may also be found as wolfram or “wolf dirt”. It was known and detected in wolframite about 250 years ago. Currently, one can find a few collectible species with considerable tungsten in their chemistry. Oliver Sacks called Nature’s Building Blocks by John Emsley (2001) “A marvel ... sheer delight.” Excerpted above, readers find a bit of Emsley’s chapter on tungsten.

In Ford, 1966 [Dana’s Textbook of Mineralogy] we find eleven species in Appendix B. Wolframite and scheelite are the two major species indicated on the list. It is noteworthy that currently we would redefine wolframite as presented by Ford, in a different manner. For example, Back, 2014 [Fleischer’s Glossary of Mineral Species] indicates wolframite is a mineral group with five species; collectors are most familiar with ferberite and hubnerite. One may consider these as a solid solution series from ferberite, the iron-rich member through hubnerite, the the manganese-rich member. Fe–Mn series are very frequently encountered in nature; this is but one example known.

The strategic importance of tungsten, particularly in relation to armor piercing weapons and armament might surprise you. An interesting historical example – “Why was Nazi Germany short of Tungsten?” – can be found at: http://forum.axishistory.com/viewtopic.php?t=163333. 

Collectors seeking fine examples of ferberite, hubnerite and scheelite will probably be pleased to note that I think they are all reasonably available at most any mineral show. And, most other tungsten species are generally classified by me as being of minor importance for a collection.

Historical perspective here might of interest: Sinkankas in 1964 [Mineralogy for Amateurs] suggested “good specimens of their compounds (molybdenum and tungsten) are relatively scarce”. Bolivia, Bohemia and Colorado were his choices for the best examples (in 1964) for wolframite group members. Scheelite is indicated from Connecticut, Utah, California and Arizona. Worldwide, we find England, Bohemia, Italy Spain, Japan and Korea. Illustrated we note a crystal from Mexico. 

More recent finds perhaps eclipse these older localities in size, quantity and even quality. Consider, if you will, ferberite from Portugal and Kazakhstan along with hubnerite from Peru. What will we think about Chinese, Russian and Pakistani scheelites found and made available in the last fifty or so years? Bernard and Hyrsl, 2004 [Minerals and their Localities] mention, in addition to the localities above, South Dakota, Germany, France, Spain, Uganda, Rwanda, Peru and Japan. For hubnerite, South Dakota, France and Montana are among their selections.

Moving to scheelite, a long list can be found with Nevada, Namibia, Uzbekistan, Brazil, Australia, Peru, Malaysia, Romania, Austria and Pakistan as well as others. One might properly conclude that these three species are in fact more available now than they were fifty years ago. On mindat.org, the number of localities given for wolframite is 1632 while scheelite has 4266. 

Locally, Trumbull, Connecticut has produced scheelite of some note as well as ferberite after scheelite. Not much else is of concern to me but the probability of additional localities is likely. Some years back, I found multiple minor occurrences of scheelite in and around the famous mine in Trumbull. 

Type Minerals

By Bill Shelton

Arizona has some fame for type minerals; there are nearly 50 that I know about.  Ajoite, from Ajo, is a good example.  Yedlinite, from Tiger, is a striking example of a rarely seen mineral.  Bideauxite, also from Tiger, is an example with rare chemistry and mostly tiny samples.  Paramelaconite is a type mineral from Bisbee.  Places like Tiger and Bisbee often produce more than one type mineral.  Papagoite is another type from Ajo.  Shattuckite is known as a type from Bisbee; surprisingly it also occurs at Ajo and San Manuel (near Tiger)!  Collectors may feel drawn to localities like these and perhaps will even collect samples of these minerals.  

What is a type locality?  This designation refers to the first place where a mineral was discovered; it also must be recorded in some text, etc. having been studied and, later, accepted by the mineral community.  Recently, that implies the IMA.  Prior to 1850, some type localities are unknown.  Also, a small percentage of minerals are known for a very long time; hence they might be entitled to a designation like “known since antiquity”.  Gold, silver, copper and lead are a few examples that are classified as native elements.  There are some other elements that belong here.  One oxide, corundum, also falls in the known since antiquity class.  Almost all minerals have a type locality – Pekov (1998) states there are 582 type minerals from the former Soviet Union.  However, only 482 type specimens exist.  Mostly we find old minerals (18th – 19th century) do not have type examples in museum collections.  The Fersman Mineralogical Museum has 385 type species while the St. Petersburg Mining Institute has 225 examples.  See Minerals First Discovered on the Territory of the former Soviet Union.  Finally and perhaps most important: a type mineral must be from the type locality. 

The type specimen(s) refer to the exact piece(s) that was originally studied – hence we might expect there is only one of perhaps a very few pieces for each species.  It is not uncommon for little pieces to be removed and sold as part of the type.  It may interest you to know that additional pieces used for revisional studies (sometimes documented as neotypes) may be included under the type specimen designation.  Commonly, collectors may have a sample of a mineral from the type locality – it clearly is similar but technically not the type mineral.  Because these pieces are much more likely to be available, a collector can amass quite a lot of examples – and they may call them type specimens. 

Definitions about type specimen mineralogy.

Holotype – a single specimen from which the original description of the mineral can be determined in whole.

Cotype – multiple specimens from which quantitative, but not necessary, data are obtained for the original mineral description.

Neotype – a new specimen for the redefinition or reexamination of a mineral when the holotype or cotypes cannot be located or, upon examination, are inadequate for study.

— Wikipedia, 4/4/2016

As an example, crocoite was originally described from the Tsvetnoi mine, Uspenskaya Mt., Beresovskoye gold deposit, Middle Urals.  This, according to Pekov, is the correct data.  We commonly see Beresov specimens for sale – they may be from the type locality or nearby.  I believe no type material exists today.  However, anyone can acquire a crocoite from this area today if they choose to do so.  

If we choose to accept a general definition, then we can have a lot of examples form some species, like crocoite.  This material has a good potential for collectors and, I believe, some scientific value.  If you know the type locality, it will be simple enough to try and find a sample of a given species.  

It can be a bit tricky to do this for some minerals.  Columbite, formerly a species and now a mineral group, is a good example.  The first material came from an area near New London, Connecticut.  Since it was redescribed, we have ferrocolumbite with the type locality of Western Australia.  Also, there is magnocolumbite with a type locality of Kuki-Lyal, Pamir, Uzbekistan (?) and manganocolumbite without a type locality given.  This is all according to Blackburn and Dennon (1997) in the Encyclopedia of Mineral Names.  I would vote for New London as the type locality for ferrocolumbite because the original piece is probably this species in modern nomenclature.  Much “columbite” in this region is properly labeled ferrocolumbite.  Dana’s New Mineralogy claims the New London locality for ferrocolumbite and indicates magnocolumbite has a type locality of Kukh-i-la, southwestern Pamir Mt., Tadzhikistan.  There is no data for a type locality for manganocolumbite. Further, Pekov confirms the magnocolumbite locality but calls the place Kukhilal gem spinel deposit, Pyandzh River valley, SW Pamir, Tadjikistan.

The Handbook of Mineralogy sometimes indicates where type material is located.  For ferrocolumbite, it is the Natural History Museum, London, England.  It is not given for the other two species.  Pekov does not tell us where the magnocolumbite type specimen is located; he indicates this information for most species in his book.  One should assume all the data is available – finding it may be a problem.  I’m still not sure where the manganocolumbite type locality is for example. 

Using mindat.org, you can see the “most prolific type localities”.  Perhaps you will find these examples interesting.  Tsumeb has 70 types and 284 species while Mt St. Hilaire (including Poudrette) has 65 types and 400 species which is the second most on this list. The Clara mine has the most at 405.  For contrast, Franklin mine indicates 36 types and 173 species and the Sterling mine has 22 types and 229 species.  Surely some listings clump Franklin and Sterling together as if it was a single place.  If you clump the Kola localities as a single entity, it will easily win and I find over 10 places on the mindat list from the Kola region. Langban, Sweden wins with 72 types and 287 species which is the highest number of types on this list.  Again, you may be frustrated; for example the list of 100 localities tells you that the Kirovskii apatite mine has 16 types and 84 minerals.  Click on the name and a detailed list comes up where it says there are 19 types and 112 valid minerals.  The Kovdor Zheleznyi mine (Iron mine) has 13 types and 55 valid minerals; it is located near the border with Finland but could be grouped with other “Kola” localities.  Pekov says that Khibiny and Lovozero (together) have 118 types as of 1997.

Bernard and Hyrsl (2004) tell us the “Richest type localities of the world” include Lovozero (90 types) with 41 from Karnasurt and 24 from Alluayv.  Khibiny has 80 with 20 from Kukisvumchorr and 21 from Yukspor.  Langban has 72; Tsumeb has 59; Franklin-Sterling Hill has 58 and Mt. St. Hilaire has 43.  So, where you choose to look may produce anomalous results.  Recent investigations can increase the total for a locality – a few places get a lot of attention; i.e. Tsumeb.  Despite some lack of agreement, it is clear that a few places, whether considered as single places or combined regions, are the most prolific in the world.  It would make sense to me to rethink the system used and look at the data in a single, unified fashion.  I would like each mine, etc. to be a single entity and this seems to be the inclination of the mindat list.  A place like Lovozero includes many individual sites and should not be considered equivalent to a single quarry site such as Mt St. Hilaire.  In any event, you now have the names of a few places that are really famous for type species and can embark on your own crusade to perhaps acquire a set of type locality samples.