Inky blue swirls and whorls make this Agate slab stand out from the rest! 

Agate is a form of quartz silica appearing in a cryptocrystalline structure and forms in microlayers over the course of 50 million years in the hollows of large rocks, slowly filling the space as groundwater rich with minerals seep in and crystalize. These layers are often colorful and can form thick bands, just like in this specimen. Different mineral compositions tint the bands, showing the history of the agate in a visually pleasing way.