Very little is known about Coyamo thundereggs
since they were on market in the past for only a short time and it didn't
help that most Mexicans are interested only in just selling, not providing
any geological information. Most thundereggs are hollow, lined with thin
layer of agate and druzy quartz, and very few thundereggs are found with
solid white agates. I managed to find one with pinkish hue.
