Sphene

Sphene (スフェーン, Sufēn) is an Off Color Gem currently stuck on Earth, who was previously sent there to investigate 'unknown Gem activity' occurring around the planet's atmosphere, which was likely the Elementals. They somehow ended up crash-landed on Earth, and are now looking for a way to get off of the planet. Sphene is also an incredibly young gem, being the second youngest in the group of Gems on Earth.