The Galilean Moons gift box showcases the famous Galilean moons of Jupiter, discovered by Galileo. The moons are represented by tumbled gemstones:Io: Yellow JadeEuropa: Red HowliteGanymede: Bamboo JasperCallisto: Leopard skin JasperGalileo discovered these moons using his telescope in January 1610. Thereby demonstrating the value of using a telescope to observe the cosmos.