Quartz

Quartz is a pink ore, which spawns from 300 to 500 meters depth. It's appearance consists of a few pink crystals, along with a bigger one in the center. It is used in base upgrades, like in Mining Operations.

Quartz in real life
Unlike ingame, real Quartz is actually transparent and grey. It is commonly used for jewelery. It's 7/10 in the Mohs Hardness Scale. (10 being diamond)