This gem's patterns of rainbow-colored brilliance change depending upon the viewing angle.
These very changes are an important component of Mexican opal's beauty.
Some of the opals from Mexico exhibit a beautiful play-of-color effect, showing patches of red, orange, yellow, and green when polished as cabochons. Those with a bluish body color are called "water opal," and orange-colored ones are referred to as "fire opal." The Aztecs, whose civilization flourished in modern-day Mexico from the mid-14th century until 1520, used opals in their jewelry. Development of the Mexican opal mines was renewed in about 1850.

Mexican opal's beauty lies in how the brilliant patterns of colors seen in these highly transparent gems change with the viewing angle. In water opal, it appears as if the flashes are trapped in clear water; in fire opal, they appear to be trapped within a flame. The patches of color generally become weaker in more transparent stones, and high-quality pieces are rare gems that manage to combine these opposing features.

Around 1960, there was a surge in the popularity of Mexican opals, and Japanese consumers were especially fond of them. At the time, its popularity in Japan was said to be surpassed only by that of diamond, ruby, and sapphire.
However, Mexican opal's marketability suffered after 1970 because of repeated cases where cracks developed due to a loss of water content. Details varied widely, with some stones developing cracks immediately after being polished, others after a few years of use, and so on. These days, rings set with Mexican opals are often brought in for remodeling or remaking, a fact that attests to the popularity once enjoyed by these gemstones.

Newly polished Mexican opals are reappearing in the marketplace, though on a small scale. The opal miners know which exact spots produce the best material, and rough stone prices reflect this. Cutters who are concerned with their reputations buy rough material that they know will not develop cracks, and polish them only after confirming their quality over a period of three to four years. This is another example of how "who you buy from" is more important than "what you buy" when it comes to gemstones.

It is important to wear Mexican opals to give them natural moisture. When cleaning opal jewelry, it is best to use a soft brush with mild soap, avoiding ultrasonic cleaners.
Ring, Platinum
Mexican Opal 1 pc
Estimated Weight: 6.50 ct
Diamond 6 pc
US $15,000