Adamantane is a colorless, crystalline chemical compound with a camphor-like odor. With a formula C₁₀H₁₆, it is a cycloalkane and also the simplest diamondoid. Adamantane molecules consist of four connected cyclohexane rings arranged in the "armchair" configuration. It is unique in that it is both rigid and virtually stress-free. A boat-shaped configuration can also exist. Adamantane is the most stable among all the isomers with formula C₁₀H₁₆, which include the somewhat similar twistane. The spatial arrangement of carbon atoms in adamantane molecule is the same as in the diamond crystal. This motivates the name adamantane, which is derived from the Greek adamantinos (relating to steel or diamond).