Las Choyas: GEODES 101

Geodes are popular no matter what the type. It's hard to resist the mystery and challenge of what's inside these rather plain-looking round rocks.

- RICHARD GROSS

Arguably though, Las Choyas Geodes are the most popular, attainable and collectible geodes available to geode enthusiasts.

These Mexican geodes found in one small area just slightly north and east of Chihuahua city are known in the trade as "Mexican Coconuts." Collectible in this case does not mean field collectible as production is pretty much confined to one area owned by one family.

Most Las Choyas geodes for sale in rock shops and gem and mineral shows are between 2.5 and 3.5 inches in diameter although they can range up to six inches in diameter. Almost all are spherical in shape thus affirming our concept of what shape a geode should have. Because the opportunity for field collecting is not available to the general public, most hobbyists will usually only have a few Las Choyas geodes in their collection.

The word geode comes from Ancient Greek and means "earthlike." For the metaphysical believer, geodes, like Las Choyas geodes, are said to bring flow, harmony and resilience to the bearer.

HOW LAS CHOYAS GEODES ARE FORMED 

Unlike the famous Keokuk geodes that form in a sedimentary environment, Las Choyas geodes form in an igneous environment. This environment comes about as a result of a volcanic eruption producing an ash flow that contains bubbles that are trapped in the rhyolitic tuff rock formation when it solidifies. These hollows in the rock provide the chamber where the mineral-rich fluids flow to start the process of geode formation. The total process may take millions of years and involves a complex series of geological events that ultimately yield these spectacular geodes.