Thanks for the input, Dennis. And yes, that is what we have always assumed as well.
But, now, with the possible presence of "black" rutile we are looking at the "schorl" much closer.
Is it all schorl? It could very well be, but there are inconsistencies.
Could some of it be Black Rutile? And the "layering" I see in many of the crystals reminds me more of Ilmenite? And there are other possibilities.
Hopefully, eventually, there will be several correct answers identified.
I will try and find some pics of the schorl from Hiddenite, and try and find my own self collected pieces, for comparison. Good idea!
I have been looking at many pics on Mindat lately for comparisons.
Here are two pics from Mindat. The first is a stunning complicated schorl. The second pic, also from Brazil, I found under Ilmenite on Mindat and thought closely represented what we are finding.
And did you know there is Red Schorl in Hungary?
https://www.mindat.org/photo-24360.htmlhttps://www.mindat.org/photo-481483.htmlIt may be all schorl but may as well put in a couple Mindat pics of Ilmenite, while I'm at it.
https://www.mindat.org/photo-417988.htmlhttps://www.mindat.org/photo-4329.html