The photo above this text is of a whole Laguna Agate Nodule in the host rock, Andesite, or Basalt. These wonderful rocks form in the air bubbles from a volcanic erruption. Once the air pocket is made in the hot lava, it starts to cool. As it cools minerals seep into the open pocket and start to form a gel. This gel turns diffenrt colors for every diffent element and mineral present. Lagunas are the most sought after collectable agate. They are noted for the colors and the banding. There can be over 100 bands per square inch of surface. I am sure you will ask or even wonder if I will ever cut that one lodged in the rock open? What do you think? I am sure .... maybe.. just maybe one day I will wonder. But this is my best specimen of the host rock, and I have another I think I am going to cut up to show it open in the rock. :) Well see :)