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.