Unlike most other birthstones, opal is not a crystalline gemstone, but a mineraloid. These types of substances are formed under similar conditions as crystal gemstones like emeralds and diamonds, but possess a different chemical makeup. Other common types of mineraloids include obsidian, jet, amber and even petroleum.
Ornate White Opal Snow Queen Ring
by Little Bear's Mom
Opals are formed from ancient hot springs, and have a water content of anywhere from 3 to 20 percent. Most opals are found in dry, arid climates like Mexico and Nevada. Australia is the leading producer of gemstone quality opals, with over 90 percent of the world’s gemstones originating from Australian mines. Opal is their national gemstone.
The color of natural opal can range from white to black, with many color variations. Blue and green hued opals are more common, with reds and blacks being the most rare. The birthstone opal is usually an iridescent white or pink color, similar to mother of pearl.
Because common opals show many different colors on their surface - usually pinks, yellows and blues - they are often considered a mood stone. Opals have been thought to increase happiness, bring good luck, and even encourage love. Legends of Australian aborigines indicate that the opal is a sign of peace.
Blue Oregon Opal Necklace
by Six Baby Girls
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