A little boy who has replaced his mother in a group of gemstone based creatures must learn to control his own power. This series is set in a fictional beach city, where the immortal alien warrior Crystal Gem lives in an ancient seaside temple to protect the world from evil. They project female figures from magical gemstones that are the core of their existence. Crystal gemstones are garnet, amethyst, pearls, and Steven. Steven is a young boy who is half human and half precious. He inherited his own gemstones from his mother, who was the former leader of gemstones, Rose Quartz. As Steven tries to figure out his power, he spends every day with his human father Greg, friend Connie, other people in Beach City, or other gemstones, whether it's helping them save the world or just going out to play. He explored the abilities his mother passed on to him, including fusion (the ability of gemstones to fuse their identity and body to form a new and stronger personality).