This month's birthstone comes in so many different beautiful varieties. A few of the opals I love working with are Australian boulder opal, ethiopian opal, mexican fire opal, pink opal and dendritic opal. Opal has a long history according to Robert Simmons Book of Stones. Opals were mined at least as long ago as the fourteenth century. Mexican Fire Opal was used by the Aztecs and was brought to Europe by the conquistadors. In nineteenth century Europe Opal became less popular because of the association with bad luck. In Roman civilization, Opal was linked with good luck and hope. The belief in France that Opal could render its wearer invisible allowing them to steal without being caught, may have been the beginning the the negative association. An Australian legend says a gigantic Opal governs the stars, human love and the gold within the mines. Current metaphysical thinking gives each type of Opal different energetic properties.