Ancient Treasure: Mexican Opals
The Maya and Aztecs revered the opal stone because they believed that it came from heaven from a flash of lightning; others believed that wearing the glittering stone would bring prosperity or ward off illness. Other cultures believe that the opal symbolizes purity of love. Most people wear opals simply because the stone is so beautiful!
Mexican opals are one of the few varieties of opal that can successfully be faceted, as some specimens can exhibit considerable transparency. The prices and value of Mexican opal vary according to the size and quality of the gemstone, with the vivid orange and red colors being the most valuable. 
The ‘common’ milk white opal that is used to make jewelry is prized for its characteristic ability to reflect beautiful array of colors. These semi-precious stones are made of cristobalite spheres of varying sizes and appear to have a random distribution pattern throughout the mass of the stone. The most prevalent type of opals carry what’s known as ‘opalescence’. This effect occurs because the stone is one solid color but reflects a variety of shimmering colors at the same time. 
On the other hand, the fire opal stones are far rarer than other colors of opals. They are defined by the phenomenon known as ‘play of color’. This means that the stone could possess spots, flashes, sparkles or even patterns of different pure colors that surface when you hold the opal at different angles. Furthermore, the fire opal’s natural colors are far brighter and vibrant and reflect the shades the stone. 
In Mexico, the opals are mined in the states of Hidalgo, Queretaro, Guerrero, Jalisco, Michoacan, San Luis Potosi and Chihuahua. Mexican opals have numerous positive attributes and meanings for their wearers. The most significant meaning, and the one for which it’s become most popular, is a representation of the joy of the heart. It symbolizes passion and love not only for others, but for different elements of life, including careers and hobbies.
When the Spanish conquistadors arrived in Mexico, they were impressed with the exotic Aztec and Mayan adornments and immediately began plundering the brilliant opals. Rather than give up their sacred stones, the indigenous people cleverly simply stopped securing the gemstones, so that all the known locations for opals were lost with the dying indigenous civilizations. It wasn’t until 1840, that Sir José María Siurab rediscovered the deposits and started to work the Mexican mine, Santa María Iris, at Hacienda Esmeralda, in the Mexican state of Queretaro. Another rich deposit was discovered in the mid-1800s on the hacienda; this one location supplied the majority of the world’s opals for the next hundred years. The region reached its peak production by 1969 when additional opal deposits were discovered in other Mexican states. For those of us in the Riviera Nayarit, the Puebla of Magdalena, Jalisco is an easy day excursion where you can tour a mine and buy wholesale opals.
Opals occur worldwide primarily in volcanic areas where past eruptions caused water to be suddenly trapped within the silica base. The Mexican stone can be characterized as more translucent and jelly- like. The best Mexican opals exhibit an excellent play of color that looks like thawing ice: a luminous surface that appears to be dripping.
Although Mexico produces exceptional opals, the tourist needs to be aware that some street venders will sell manufactured, synthetic opals. “Genuine, quality Mexican opals are typically set in a base of other material to give them strength and help reflect the light,” explained La Penita master jeweler and gemologist, Armando Gonzales, of Armando’s Joyeria & Relojeria on the main avenida. You can visit his shop every day of the week or email Armando-joyas@hotmail.com, or telephone: 327-274-0104. (English spoken.)
Looking at an opal is similar to looking at light passing through water drops in the sky to form a rainbow. If you have an opal, you possess your own rainbow! Few gemstones evoke the excitement of a precious Mexican opal. The flashy show of this gem makes each specimen unique, a fountain of mystery, enchantment and legend. Treat yourself or someone you love to the beauty of Mexican bling.