Before the events of 2020, we decided we would send a sample to the GIA (Gemological Institute of America) and have it analyzed so we would know once and for all what it was. But ... we put it on the back burner as a priority, with lots of other things captivating our attention during that year. Finally, we chose a small piece, shown in the hand in the photo, and sent it off. It was mostly purple with some of the black, plus a couple spots of blue (though we have found very little of the material has the blue).
And while I would like to say the mystery is resolved, ... the results were rather surprising to us. Per the GIA, it was identified as: "Dumortierite, Tourmaline, Rutile and possible additional minerals." We asked some questions and got an additional answer from them that indicated the black stuff in the small sample was Tourmaline and the stone is mostly fine-grained, so they couldn’t take the identification any further. We assumed the small spot of the rarely-found blue in the little piece was the Dumortierite, and we were very surprised that the black was Tourmaline - presumably Schorl (the name for a type of tourmaline that is black). In the majority of the material, there are different shades and patterns in the black, such as tiny spots or orbs of black and pink, and some of it even looks a little blackish-olive-green. The pieces are heavy, so we still think the material has quite a bit of Manganese.