When amethyst occurs in bands with white quartz, it's called banded amethyst, and when it forms an elongated point, it's also called "dogtooth amethyst". We had one of Waffle's teeth removed, so I can attest it's true!
The "V" shaped patterning is natural and also is called CHEVRON amethyst, and it's such a striking combination with both the energies of the purple and white quartzes! The white quartzes can range from clear (crystal quartz, which you may have seen before, as it's a very popular stone) to a white "snow" quartz that is more opaque.
