Some believe that amethyst causes cell division. If so, then amethyst should not be worn alone, but coupled with calcite, if you have cancer, have had cancer, or have a family history of cancer. See the book, “Rock Medicine”, by Sela Weidemann Randazzo for more about stones and their healing properties.
Due to this potential for danger from amethyst, I list the specific stones included in each piece of jewelry, if I know them. Amethyst is fairly easy to identify, although, some purple fluorite stones can be confused for amethyst.