Hardness 7 Amethyst are two twin Gems who mainly do patrol duty. They are individually named Eighty-Four and Thirty-Three. They're two in one and partnered with each other. According to Yellow Diamond, twin Gems will not break when they touch each other, as demonstrated when the twins bash their heads together, much to the chagrin of their observers. They are both great at swordplay and were recommended to train Phos for a short time. The twins work in tandem for a lot of things, often talking at the same time or finishing each other's sentences. No one really cares which is which anymore, including themselves.

Spoiler

Later, Eighty-Four switches their hairstyle to deceive Phos in order to go to the moon in Thirty-Three's place. On the moon, Eighty-Four has learned to become more of their own individual and serves as an assistant scientist there. They seem to be highly interested in more of the psychological aspects in the science field.