Types of Opals - Which is Perfect For What Type of Opal Jewelry?

Opals are striking gemstones which flash with all the colors of the rainbow. They are made from tiny spheres of hydrated silica; silica being the sand constituent that makes up sand! As they form, tiny droplets of water become trapped within the lattice work of spheres in an irregular pattern. The water diffracts light passing into the gemstone, resulting in the magical play of color, known as opalescence, for which this gemstone is famous!

However, not all opal necklace are the same! There are four broad categories of opal, white, black, boulder and crystal, which differ in their translucency and color of the host rock. They also exhibit different levels of opalescence. And although fashion dictates the changing popularity of individual opal types, certain types of opals lend themselves better to some rather than other forms of opal jewelry. So which form suits what jewelry best?

White opals are the most abundant of these gemstones. They have a milky white appearance which can range from near opaque to translucent. The more milk like the backdrop of the host rock, the harder it is to see the flashes of fiery opalescence within. Their beauty is most readily seen in strong direct light. Their pale appearance and relative affordability means that they are often set, as cabochons, into silver metal for everyday pieces of jewelry.

Black opals are the rarest, most coveted and most expensive form of the gemstone. Some of the best in the world come from Lightning Ridge in Australia. The dark host rock is usually black, blue, brown or gray and provides the perfect backdrop against which to see the glorious color display of these gemstones. They have the look of an angry storm cloud behind a rainbow.

The drama of black opals is best appreciated in full view. They are typically set as cabochons. And they are dramatic enough to hold their own even alongside diamonds in a signature piece of fine jewelry, such as a wonderful anniversary pendant or an engagement ring.

Boulder opals are always cut with some of the host rock still attached. They are typically set into jewelry as thin segments or as baroque stone shapes. They are unusual and extremely attractive pieces which will draw comments and admiring glances! They cannot easily be set into rings but make superb pendant necklaces.

Crystal opal types, such as fire opals are transparent and typically have a good clarity which allows a strong diffracted color to be seen. These are the only category of the gemstone which is generally faceted before being set into jewelry. Fire opals have little opalescence but are instead valued for their color. They make wonderful rings, earrings and pendants.