There is no other gem like opal-it alone is capable of having all of the colors of the rainbow within it. This "play of color" is due to ordered molecules refracting light from this opal lattice. The light is broken up into its component parts, much like a prism effect. Therefore, it is possible to see a complete rainbow of color when the opal is viewed.

Although opal is found in many parts of the world, including the U.S., much of it is not stable. This means that the opal will craze over time. Crazing describes fine cracks or lines occurring within the gem, rendering it worthless. Reputable dealers will guarantee their opal to be stable and will not craze. Do business only with people who are knowledgeable about opals because the pricing is highly dependent on such factors as body color, play of color, size, pattern, and distribution of color.

Body color refers to the underlying color of the opal which can be white, gray, semi-black, black, blue, and orange. Play of color refers to the range of colors that are observed moving within the gem. Such colors as red, green, blue, yellow, and orange are observed in opal. Some opal will have great color but it will not be evenly distributed. There might be a dead area where there is only potch (opal with no play of color). Top opal will have a strong play of color against the background body color and it will be evenly distributed across the gem. The pattern of color can vary from showing a rolling flash effect to discrete blocks of color (often called harlequin pattern) to pinpoint and other patterns.

Lucky is the person whose birthstone (October) is opal because in one gem they can enjoy all of Nature's colors. Opal should be worn in a protected mounting because of its relative softness and it should not be subjected to extremes of temperature. Avoid keeping opal in a very dry environment (such as a bank lock box) since this tends to draw moisture out of the gem and encourage crazing.

Synthetic opal has been around for a very long time and can fool the unwary. Just recently it was discovered in jewelry being offered as natural opal in some Caribbean gift shops. Much synthetic opal can be distinguished under magnification by its characteristic appearance, a "snakeskin" type pattern that once seen is not soon forgotten.

Top quality natural opal is not a mass produced item. So it is difficult to match gems for earrings and pendant combinations and very difficult to replace an opal that has been lost or stolen with one of equal size, shape, quality, color and pattern and distribution of color. So treat your beautiful opals with the care and respect they deserve!