This gemstone is incredible!
I keep coming up with Tanzanite as a result from LOTS of searching.
It’s blue, purple, and reddish brown… Trichromatic? The blues and purple are the most vivid colors I’ve ever seen.
Have you done refractive index and specific gravity? Honestly from the pics, it looks like amethyst.
Tanzanite is Trichroic so get out your trusty little Dicroscope and inspect for three different colors. Back to gemology basics. 