Geodes were once bubbles in lava. Over time mineral rich thermal fluid penetrates the bubble. As the fluid cools crystals begin to form within. The type of crystal that forms inside of a geode is dependent on which dissolved minerals penetrate the bubble at the time of formation. In the case of the Las Choyas Geodes (aka Coconuts), there were many different minerals present during formation making it difficult to predict what crystals you can find inside. It's a surprise every time one is opened which is why it is one of the top rated break open geodes in the world! These geodes are offered for sale in Bulk or Wholesale, wholesale geode and bulk break open or whole geodes.
Check out the geode mining process: http://www.gemsgeodeswholesale.com/geode-mine-process/