I almost got poked by a few of them while snorkeling on Big Island, though they do look pretty. Colobocentrotus atratus, the helmet urchin or shingle urchin, is a species of sea urchin in the family Echinometridae. In Hawaii it is known as "kaupali" which translates as "cliff-clinging". It is found on wave-swept intertidal shores in the Indo-West Pacific, particularly on the shores of Hawaii.
Amethyst is a natural tranquillizer, it relieves stress and strain, soothes irritability, balances mood swings, dispels anger, rage, fear and anxiety. Alleviates sadness and grief, and dissolves negativity. Amethyst activates spiritual awareness, opens intuition and enhances psychic abilities.