Opal gets its name from the Greek word opallios. This roughly translates into “to see a change in color” as demonstrated when you spin an opal. Opal forms when water picks up silica dioxide and deposits it into open voids or cavities along with trace impurities. The water then evaporates and leaves the silica dioxide. Most of the opal in the world is produced from Australia, where seasonal rains make it common for water to leach out silica and deposit it into cracks within the ground.
The October birthstone’s dramatic play-of-color has inspired writers to compare it to fireworks, galaxies and volcanoes. Bedouins once believed opal held lightning and fell from the sky during thunderstorms. Ancient Greeks thought opals bestowed the gift of prophesy and protection from disease. Europeans long maintained opal to be a symbol of purity, hope and truth. Hundreds of years ago, opal was believed to embody the virtues and powers of all colored stones.