It was just a small book produced by the Smithsonian and devoted to gemstones. The amount of information had to be limited, but I always scan such an introductory book on gemstones for its tourmaline presentation. Well the Smithsonian failed to live up to its reputation again.
The main area of the book on tourmaline has three sections labeled Elbaite, Schorl and Dravite. In Elbaite section they mention that most gemstones labeled tourmaline are cut from Elbaite. Then they bring up Liddicoatite which is a minor species of tourmaline. It is interesting that they want to discuss a species of tourmaline that is so closely linked to Elbaite that they mix together across sections of crystals without noticeable change in gemological properties. Well they went there and they are correct, but if we are talking about species of tourmaline that are made into gemstones, you must talk about “chrome” tourmaline which is the species Dravite with an exceptional green color. (It is not discussed)
Now why did I specify the species Dravite, because there is a traditional varietal name for brownish tourmaline called dravite. Most cut dravites are brownish Elbaite, but the trade decided to associate brown with the species Dravite years ago and without an inexpensive method to separate the species it stuck. Now as I was thinking about this, I turned the page and was looking at a page labeled Dravite (After the schorl page that is not too interesting with regards to gem quality tourmaline). So the nomenclature issue, which is a bit much for an introductory book, is going to be discussed? Well the page treats dravite as a variety of Elbaite including the statement that most Dravite comes from pegmatites. This is completely wrong if you are talking about a completely different chemical from Elbaite, that is called the species Dravite (even in Mineralogy). Dravite, the species, is a contact metamorphic mineral which is an entirely different geological setting for a tourmaline than Elbaite which is pegmatic. OK so you give the museum a break and say that they were talking about a variety of Elbaite not the species. But if you mention dravite in that sense you have to include much more important varieties such as Rubellite, Indicolite etc. These varieties are not given their own pages, even if they might be mentioned somewhere else in the book.
Now if you’ve gotten this far down this post you may be thinking that I am getting pretty picky in my old age. And I am, but a great institution should not sow confusion and misinformation in any of its publications, let alone a simple introduction to gemstones. The world of tourmaline is complicated and you must be careful or you will just add to the confusion, even in a brief attempt at education.
Bruce
