The name opal comes from the Greek word opallios which means “to see a change of color”. According to Greek mythology, when Zeus defeated the Titans, the Greek god of lightning was so content that his tears of joy formed the gemstone opal.
Play of Color
Opals have a water content ranging up to 30%. This water content is responsible for opal’s signature feature, the play of color. If this water content were to decrease or diminish, opal would crack and the interplay of colors would disappear. A great number of studies have tried to find out the reason behind this phenomenon. In 1960's scientists have discovered the reason behind it. They have determined that opals were composed of small silica spheres formed in an organized manner, and they put an end to the question which echoed throughout history.
Australian Aborigines believed that opal was the footprint of the creator. Currently, Australia is the country which produces almost 95% of all the world’s opals. Most of this opal is located in Coober Pedy in South Australia.
Opal has a hardness rating of 5.5 to 6.5 on the Mohs scale, which makes them very brittle gems. They are very sensitive to light, so they should not be kept under direct sunlight. They should not come into contact with oil or cleaning products. Among all the gemstones, opal is easily the one that calls for the most care. Since contact with heat would evaporate the internal water, processing them calls for great care. Opals are also sensitive to pressure and impacts which is why safeguarding them in a humid cotton fabric is crucial for them to not get damaged.