Very inaccurate discovery site data - like these: northern Chihuahua - are reducing the scientifical value also of the most beautiful specimen. If you can specify any detail on this website, please contact me. If Your data is verifiable it will be published.
The agates described here are small Thundereggs. Their pattern is dominated by whirly chalcedony. Only in the center of these lithophysae banded agate in brownish to whitish colours is showing up. They are reaching sizes up to 60 mm in diameter. Their skin is greyish to brownish. Chalcedony-veins are reaching the surface.