Unlike traditional gemstones such as diamonds or sapphires, opals are a hardened silica gel with a water content of 5-15%. Opals are prized for their kaleidoscope of colors and have been compared to galaxies, fireworks, and even volcanoes. Australia, Brazil, Mexico, Africa, and the United States are the largest producers of opals since the 19th century. Due to the presence of other colors in unpredictable patterns, no two opals are created equal. However, there are five main categories of opals: White/Light (translucent/white background with several colors), Black (translucent black with several colors), Fire (transparent/translucent with brown, red, yellow, and orange), Boulder (transparent/opaque with several colors), and Crystal/Water (transparent/semi-transparent with exceptional colors).
The unique “play-of-color” in the stones is due to the layering of small, stacked spheres; as waves of light travel through the spheres, the waves bend and break into the various colors of the rainbow. The size of the spheres determines the color reflected.
Due to their myriad of colors, opals have historically represented change and new beginnings. Romans have admired and described the opals deep, rich colors as early as the 1st century A.D. Other cultures believed opals to possess supernatural powers. Arabic legend states that opals fell from the heavens in lightning. Ancient Greeks believed opals protected the wearer from disease and bestowed the gift of prophecy. Regardless of culture, opals have been widely considered to be the luckiest and most magical due to their color displays.
Although opals are most commonly represented as the birthstone for October, its use in engagement rings is rapidly growing. In addition to representing change and mysticism, opals also symbolize love, purity, and truth, making them an ideal choice for engagement rings.
Since opals are prized for their plays-of-color, stones with desired quality and ratios of color will be considered the most valuable and the highest cost per carat. Type, Transparency, Clarity, and Cut are also very important factors to consider when choosing the ideal stone.
Opals can contain inclusions, as do other precious gemstones. A skilled jeweler/gemologist will be able to determine the best cut that reduces weight while maximizing color. Although opals can be cut into irregular or unusual shapes, opals are traditionally fashioned into symmetrical, domed, oval shapes. Your jeweler will also be able to help you care for your opal engagement ring. Due to their higher water content, opals are more prone to breakage and should be well-maintained.