Yes, yes, yes, Could not agree with you more, Laurie.
I, of course, do not have the ability to do the comprehensive analysis needed to answer this question. And I have always looked at the tourmaline from the Crabtree as schorl. But now, finally getting around to taking a closer look, I would say there is very little schorl.
As you can see, from the article cited by Dennis, Fluor-Dravite is a very "new" mineral, 2011. In the article from Mindat that I'm linking you to below it is stated that The Big Crabtree is the type locality for this new tourmaline classification. In the Clarke,Hawthorne, Ottolini article they talk about finding only minute millimeter sized grains of the Fluor-Dravite in limited contact areas, but in the Mindat article they tested all different specimens of the tourmaline and report that it was "all" this "new" dark brown tourmaline, and that is exactly what I am finding.
Here is the Mindat link,
https://www.mindat.org/a/best_fluordraviteWith my very limited scientific knowledge and abilities,
,
I can safely say that at least 50% of what I'm finding in my specimens from the Crabtree are a dark brown translucent tourmaline, sometimes transitioning to green, and am guessing the percentage to be much higher. It is definitely not all schorl.
Some of the tourmaline crystals have a brown translucent 1-2mm thick "rind" on the outside and a degraded opaque black interior, so I do not have any idea what is going on there.
I need to make some good specimen pieces for the tourmaline and hope to get working on that soon, but here are some really poor pictures that you might be able to see some of what I am talking about.
The first picture is of some random samples of Crabtree pegmatite. With a good light and a loupe you can see that 'All' the tourmaline in those pieces are a dark translucent brown, or Fluor-Dravite for lack of a better name.
The last two pics are of a thin section I cut. Sorry about the quality of the specimen and pictures, but this is very typical of what I am seeing in the tourmaline once cut.
I want some Schorl! I'm looking for schorl in this stuff, but don't know if I have found any yet?
This really is a great topic for discussion. Dennis and I have been batting it around for a few years, and I am finally getting around to taking a closer look. Several years ago, after talking with Dennis, I went in search of scientific research done on schorl and dravite and found an article that concluded there could be a dozen different chemical signatures between the schorl and dravite series and that it would take years to identify and distinguish them all, if any one wanted to. Hopefully more work will be done on specifically the tourmaline from The Big Crabtree.