Here is a Mexican Opal Nugget with awesome Play of Color! Look at video to see for yourself. Notice the characteristically Mexican clarity of the Base “Color”. There is no color! its completely TRANSPARENT.

Weight: 1.470 CT

Size: 7.25 x 8.45 x 5.15

Origin: Magdalena

Brightness out of 5: 4.5

THE GEOGRAPHY OF MEXICAN OPAL: The two main mining areas in Mexico that produce these precious opals are Querétaro and Magdalena, situated in central Mexico, northwest of Mexico City and Guadalajara respectively. These historical deposits have been coveted by the native families for over a hundred years. They consistently produce oranges, reds, and blues with little or no play-of-color, while sporadically producing the wild, full-spectrum patterns of color seen in the rare opals.

MEXICAN OPAL GEOLOGY :

The opals crystallize in a hydrothermal system where the hydrous silica gels get trapped and concentrated in cavities and fractures within rhyolitic lava flows. This unique geologic process then “freezes” the opal melt from the high temperature solutions that begin at around 160°C. The opals often have one- and two-phase inclusions with trapped remnants of aqueous liquids, water vapor, carbon dioxide, and sodium chloride from the original solution. The Querétaro district is one of the only significant sources of gem-quality “fire” opal to originate from an igneous or rhyolitic source. The Magdalena district has a similar geology, producing exceptional fire opals and, in rare cases, “water” and lloviznando opals as well. Australian opals, on the other hand, form at low temperatures from circulating groundwater in sedimentary-type environments.

SATISFACTION GUARANTEED! If for any reason you are not satisfied with the opal you receive, send it back and I will fully refund you. Simple and Easy!