Antique Opal jewelry colors and qualities.
#5977 
Antique Opal jewelry is very popular. Good opals may include every color of the rainbow. Quality stones flash such intense color that they often rival the fire and value of diamonds and other fine gems.
The value of opals is largely dependent on Fire Color, Pattern and Brightness. Other qualities of Antique Opal jewelry include size and setting, and don't forget condition. We will discuss the first group here.
Opals may include every color of the visible spectrum, but here are some broad groups that distinguish antique opal jewelry:
1. white is the most common, especially when flashing green. Includes cream, yellow, white and other light colors.
Try to avoid flat whites without flashes of light and other shades. A good white opal flashes color. A poor one is dull and matte and has very little value.
#6899 Art Nouveau ring
2 The most desireable of the opals and therefore the most valuable, by far, are black opals. Black opals have a dark body color, often dark blue-ish grey, that flash almost every color of the spectrum. Shades most common are blues, greens and violets. The contrasting red flash and fire of yellows and greens is most dramatic. Red flashes are the most desireable and expensive of the opals with orange in second place.
#6105 fabulous black opal with flashes of color including red.
3 I love Fire opals. These are often called Mexican opals or Mexican fire opals. Usually bright, fiery orange in tone. While they do not have the usual opal play of color, good ones have great fire and flash. Jelly Opals are part of this family and usually cut en cabochon, while the orange gems are usually faceted. Jelly opals do not have the fabulous bright orange color of fire opals, but are a much paler cousin. Again, choose gems that have good color, transparency and fire. Avoid gems that are flat and boring.
Liberty Necklace #4894 (sold) 
4. Boulder opals are the opal in it's host rock. These were popular amongst the Arts And Crafts and Art Nouveau period, used by artist-jewellers who were more interested in aesthetics than in the monetary value of a gem. The natural geological formation makes an interesting contrast to fine gold work.
Brooch/pendant #5383 (sold)
5. Opals have lent their name to a term meaning shiny and luminous: opalescent.
Here is a glass dish with sublime opalescence : #1956 
The pattern of colors within an individual stone, known as the fire Pattern, is also to be considered: Harlequin, Contra-Luz, Pinfire/pinpoint opal, cat's eye are some of the best known.
Play of color depends on the angle the opal is hit by the light. The kind of light and the way the light hits the opal affects the opal's appearance. Sunlight, clouds, artificial light of various sorts will give your antique opal jewelry a different appearance.
Your Precious Opal will look different in daylight, cloudy days, noonday open shade, tungsten lighting, halogen lighting, candle light, etc.
With every movement, the opal's color changes. To appreciate the full range of color and fire in antique opal jewelry, it's important to shake, rattle and roll: turn the piece this way and that, up and down and then do it all again.
TIPS on examining Color and Quality of Opals:
Use a loupe (magnifying glass) and look at the opal from the side. You might find that what appears to be one gemstone from the top view, is in fact a series of layered wafers of gems or even gems and glass.
To improve color and quality of poor gemstones or for financial advantage, a poor quality opal or a very thin wafer of opal was combined in layers with other gems. These layers, carefully placed underneath the opal are often not easy to detect.
When a layer of opal is combined with a layer of another gem/other substance, it is called a doublet. When there are 3 layers, it is called a triplet.
Naturally, the value of these stones is a fraction of the value of a true, good opal.
While looking at the opal from above and from the sides, examine the surface. Opals are very prone to dessication - drying out and this causes their surface to crackle and crack. While a tiny amount of crazing might be acceptable, more might mean that the entire appearance of the opal is destroyed as it is rendered dull and lifeless.
Some people claim that soaking the opal in oil will return the lustre to the opal, but in my opinion, such antique jewelry should be avoided to begin with (unless other factors superscede the opal's interest).
Antique Opal Jewelry to be continued.
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