Opal is the birthstone for those born in the month of October. Because of much superstition though, opals have been thought of as bad luck to wear if you were not born in the month of October. However, we believe in a greater power, and that that superstition is laughable and we can enjoy the fiery flash and brilliance of fine opals no matter what month we were born in.
Opal's name came from the Greek, opallios. Its meaning is "to see color change." There are many types of opals. Opals that have a white base are known as "milk" opals. Opals with a clear base are known as "jelly" opals or sometimes "crystal" opals. And "black" opals are those that have a gray or a black background. Opals come predominantly from Australia, Brazil, and Mexico. The ancients thought of opals as being symbols of fidelity and assurance. Later on in history, they were associated with religious emotion and with prayer. It was also thought to be therapeutic for eye diseases, and if it was worn as an amulet it would increase the power of the eye and of the mind.
Today, opal is thought of as a gem of unusual beauty and that many colors can flash in the same stone, allowing it to be worn in all seasons and with all fashions. The multi-colored, fiery brilliance of this stone is not from faceting, as it is with most gemstones. They receive their color through "diffraction." Diffraction is the process of passing light through opaque substances or narrow slits to give a colored display of light. This was verified a number of years ago when scientists in Australia, using an electron microscope, took pictures of fine
opals. After careful study, they were able to determine that opals consist of many small, marble-like silica (or glass-like substances) in orderly rows in layers with open spaces between. The lack of color in opals is caused by the marble-like silica solidifying in a random manner, not allowing the light to defract, thus little to no color is experienced.
Opals come in a variety of colors ranging from opaque white to very lively, deep blue hues. When buying an opal, look for good color dispersion in an even pattern and a stone that has good depth. This will prevent breaking, since opal is porous and very brittle. Opals typically have a high water content and when
they dehydrate, they sometimes crack. It's a fairly soft stone that requires special care since it can chip easily. We recommend that when an opal is not being worn, it should be left in a jar of distilled water. Or, after cleaning an opal with a mild detergent such as toothpaste or a dish detergent diluted in warm water, that after it is dried, it should have oil applied to the surface. You may use any oil such as cooking oil or Crisco, baby oil, or even natural body oil from the face or behind the ears. It's a good penetrating oil that will get deep
within the crevices and crannies of the porous areas of the opal. This is important because if going from a extremely warm to a cold or an extremely cold to a warm area, if the opal is not lubricated properly, the opal could crack, even though it has not be impacted. It is recommended that an opal that is worn
regularly should be oiled approximately once per month. If it is a stone that is put away for quite a while, you should either put it into either the distilled water solution or make sure that it is fairly heavily oiled during storing. This will help prevent it from drying out.
Opals are generally not treated in our jewelry industry. But sometimes it may be enhance by making "doublets" or "triplets." A "doublet" is an opal that has either a form of pitch, tar, paint, or some foreign substance other than the natural opal material on the back. This enhances its color. Many times you will see opals having a black dye or paint on the back side. You will see them displayed on black backgrounds. This is to enhance the matrix or the spectral beauty of the opal. A "triplet" is an opal that has three different layers: a thin
layer of opal, a layer of usually pitch, and a third layer of quartz. It's difficult sometimes to determine whether an opal is a triplet or not because it is bonded so closely and in such a way, that unless you can view the stone from the side, completely uninhibited from a piece of jewelry or prongs, it makes it very
difficult to recognize. Of course, a doublet or triplet opal does not carry the same value that an all-natural opal does. The more brilliant, the more lustrous color, and the intensity of that color (or fire, in our industry), the more valuable the opal is.
So the next time you see a beautiful, fiery, colorful opal, think about buying it,
wearing it, and enjoying the beauty of nature.