Their arms are an alloy of platinum and gold, and their legs are agate. The alloy in their arms can freely change shape. Originally possessing a bright personality, they are now calm and cold. Currently, one-third of their body is no longer gemstone. Called 'Phos' by the other Gems. Part of the battle squad. Hardness: 3.5

Kind-hearted and loves talking about romance. They have thick eyebrows, rainbow-colored hair, and wear white thigh-high socks and long gloves. Born in the same year as Cinnabar. According to those around them, they are exceptionally beautiful even among the Gems. Partnered with Bort. Hardness: 10

The strongest Gem after Kongō-sensei. A battle fanatic with a rough personality and a constantly angry expression. As the strongest Gem excluding Kongō-sensei, they are primarily assigned to the battle squad. Highly bellicose, they are admired and respected by other Gems for their strength. A Diamond class. Hardness: 10

A Gem characterized by semi-long red hair who lives in the Void. Their body emits a silver poison liquid, which they use to collect faint light to remain active at night. However, the poison is uncontrollable and affects other Gems, so they cannot stay close to others. Personality: Tsundere

A Gem characterized by a blue short cut, in charge of patrols. Usually called by the nickname 'Benito' by the other Gems.

In charge of medical affairs among the Gems. Based on mentions by others, they were originally part of a patrol duo, but became a doctor to try and heal their partner after they fell into a long sleep.

In charge of clothing. They love dressing up, so their hairstyle changes every day. They usually wear hair ornaments. Since all the Gems' outfits are based on their designs, they throw tantrums if someone's style or physique changes, insisting they must retake measurements.

The current guardian and teacher of the Gems. He takes the form of a sturdy monk and is much taller than the other Gems. The Gems usually call him 'Sensei'.