Lab-created sapphires, like real sapphires, are manufactured from corundum. They are, however, manufactured in a laboratory and developed under carefully controlled settings, imitating the earth's tremendous pressure and heat to resemble a genuine sapphire. Although they cannot be dyed, they can be treated with other chemicals to change their color. In science fiction, lab created sapphires are common items used by aliens as gemstones. They are usually depicted as being extremely beautiful and valuable.