Mined in the town of Tequila, this opal formed inside gas bubbles of the host rock Rhyolite. Adam went to the mines in 2013 and worked alongside the miners there. Mining this opal is hard work, mostly done using hand tools. The gems form in small ancient gas pockets in the host rock, which is pretty hard stuff. As with a lot of opal, you have to shift large amounts of stone and dirt to get to the gem material and this is mostly done by hand (unless you can get hold of some homemade explosives!). Because the opal cannot usually be completely separated from the Rhyolite it is ‘inclusion-heavy’.