Opal is the world's most popular, phenomenal gemstone. Writers have compared opals to volcanoes, fireworks and galaxies with many cultures associating the stone with having supernatural powers.
The Greeks believed Opals gave their owners the gift of prophecy and guarded them against disease. Europeans have considered the gem a symbol of truth, purity and hope, and the arabic legends say it falls from the heavens in flashes of lightning.
The Unlucky stone?
Many of you would have heard the saying 'opals are unlucky', but that particular superstition comes from the novel written in the 1800s (Anne of Geierstein by Sir Walter Scott) and not from ancient experiences or beliefs. In fact, throughout the history of gemstones, Opal has been considered one of the luckiest and most magical stones because it can show all colours.
Silica and Water
Opal is the only gemstone which can display a full-colour spectrum. It's hard to believe at its core, there are only a few common elements bound together in a unique, but quite variable, arrangement. Opal consists of silicon, oxygen and hydrogen in the form of hydrated silica.
Opal starts its life when seasonal rains drench dry ground in regions such as Australia's semi-desert. The showers soak deep into the underground rock, carrying dissolved silica downward. When there are dry periods, much of the water will evaporate, leaving solid deposits of silica in the cracks and between the layers of underground sedimentary rock. The silica deposits form Opal.
If the deposit contains too much water, it causes it to be unstable and can break, but if it contains too little water, it will not show 'play of colour'.
What is 'Play of Colour'?
'Play of Colour' is a phenomenon that only Opal can display. It's the different flashes of colours you see when you tilt the stone back and forth.