Kainosite is a silicate mineral that has the formula of Ca₂(Y,Ce) SiO₄O₁₂(CO₃)•(H₂O). Kainosite was first discovered in Norway on the island of Hitterø and was named by Adolf Erik Nordenskiöld (1832-1901) in allusion to the Greek word for "unusual" for its rarity and exotic composition.