Goldstone is a rare gem created under Yellow Diamond's court. He is held in very high regard. His purpose is to be a versatile scientist.

Goldstone's first major project was to research and seek an artificial cure for cracked gems. Some of his subjects were just soldiers and worker gems who hurt themselves on the job, others were cracked as punishment for misdeeds and sent to Goldstone for his research. Though he remained compassionate and careful with his subjects, many gems' cracks exacerbated and ended up shattering before he could save them. This disturbed him greatly and caused him much guilt, but he kept up a facade of being jaded by the experience.

Yellow Diamond grew increasingly impatient with Goldstone's failure to create a cure, despite his nonstop work. The Earth rebellion was getting serious, and Yellow was throwing her own gems into the war on Pink Diamond's behalf left and right, regardless of fighting capabilities. So, Goldstone was thrown into the war, under the guise of "making himself useful" and "atoning for his incompetence".

Goldstone, having never fought in his life, was lost and afraid upon being thrown into battle. He ran aimlessly and unarmed, avoiding being poofed left and right, until a small purple gem whisked him away from the fight.

The gem revealed themself as Tanzanite, a defective soldier from the Beta Kindergarten, fighting for Pink Diamond. They scolded Goldstone for being so careless before learning of his inexperience and lack of a weapon. The two became fast friends, and Tanzanite taught him how to summon his own weapon- a spiked flail. They stuck together for the remainder of the war, and barely made it to the Galaxy Warp together before the corruption blast was fired.

With the war over and Era 2 beginning, Goldstone returned to his work while Tanzanite was reassigned to Blue Diamond's court. He redeemed himself in Yellow Diamond's eyes by aiding in the development of many new tools. As a result of his redemption, he was assigned a new, much larger project- artificial fusion.

Goldstone complied with this job, though deeply disturbed by it. His first successful prototypes proved to be violent and difficult to deal with, so he requested a bodyguard. After telling his Diamond about how Tanzanite protected him during the war, she complied and pulled some strings to allow Tanzanite to accompany him as a "Cluster poofer".