Double stalactite cabochon. Would make a great pendant or ring. 27x17mm A stalactite is a type of formation that hangs from the ceiling of caves, hot springs, or manmade structures such as bridges and mines. Any material which is soluble, can be deposited as a colloid, or is in suspension, or is capable of being melted, may form a stalactite. Stalactites may be composed of amberat, lava, minerals, mud, peat, pitch, sand, and sinter.