2 left

geode - hand/display specimen of a multiple bubble filling or hollow geode

$ 7.50

Geodes are bubble fillings that weather out of a vesicular basalt. As the basalt cools, unescaped gases form voids in the otherwise solid flow. Subsequent hydrothermal activity fills these voids with mineral-rich hot water and as it cools, crystals grow on the surface of the roughly spherical void. In the basalt, the immediate zone around the now crystal lined bubble is altered and becomes more resistant than the basalt of the flow. These mineral lined geodes weather out of the basalt. Often they are completely mineral-filled. These show a particularly bubbly surface.

These are good examples of the bubble-filling origin of geodes. Because they are more expensive to ship, we are pricing them as hand specimens, economically purchased with other specimens that can ride in the same box. One is open with a quartz partial filling. The other is an example of what forms when multiple gas bubbles are touching in the hardened lava flow.

We don't have locality data other than "Mexico." 



Ships in a Regional Priority Mail box and can be combined in that box with other purchases. Click > Shipping < for shipping rates. Use back button to return to this page. 

Select a specimen: You can select a specimen by telling us what is in the photo with it, a blue or black and silver pen, a black mechanical pencil or one of those plus some number of coins, or you can let us make the selection.

Making multiple purchases? Click on the "combine shipping" button in the shopping cart. We'll send an invoice with combined shipping. A link in that invoice will bring you back to checkout, no hassle.