Calcite is a homeworld mutation experiment created by Black Pearl.

The original idea was to mutate existing gems to become more powerful; once a wide-scale scientific and military operation, the project became illegal soon after when White Diamond deemed the practices too cruel and horrific. (Possibly more due to the creations being aesthetically unpleasant than White Diamond showing mercy.)

Most of these batches of mutated gems were too unstable, and shattered or corrupted during testing. Few were unaffected, and the rest were killed or bubbled to clean up shop. The scientists involved moved on to other things, never to speak of this again else they suffer any of the Diamond's wrath. All except one, a Pearl with little regard to law. Black Pearl illegally continued their experiments, and eventually synthesized a mutated calcite from an unfinished kindergarten gem (also dug up illegally). Calcite did not seem to be much more powerful than the average gem, but Calcite was at least stable enough to remain in one normal-looking form continuously.

Calcite is a negative and dutiful stoic and member of a devious gang of mercenaries ruled under Black Diamond, a homeworld gem commander. They appear spiteful and sarcastic to most people
Calcite has a spiteful and sarcastic exterior but houses an insecure more sensitive side. Part of their mutation, their gem seems to have a dual appearance (Calcite tries to appear like a normal fusion by wearing a special visor that doubles the image of their eyes, which is something the mineral calcite actually does, look it up!). When fusing, Calcite's gem grows extra crystals budding off the original, a more frightening image to other gems than maybe would to a human. This is why Calcite dislikes fusing.

Calcite is very goal-oriented and impersonal, when Calcite gets an order from a superior they see it through to the end. Calcite hates when their teammates do not act this way, something that makes them constantly butt heads with Black Quartz and Halite, who tend to be more personal and easy-going.

Calcite does not have a weapon, but shoots magical flechettes from their gem. I guess they could take a couple and use them as daggers, but they aren't specific patterns or anything.

NOTE: musical accompaniment is base guitar and mid-pitched synth.