Up Massachusetts, as a kid, I used to find slabs of mica half an inch thick and big as your hand. That's the area, New England (and other states) where rocks are everywhere from when the glaciers melted .
Ziggy that explanation is very interesting. While the "silver mines" where the rock fossil was located in a mining town in the state of Nevada is a land- locked state miles from the ocean. Geologists refer to deposits that seen in above example pictured are the fossilized remnants of ancient coral reefs which are well-documented in the limestone strata where silver mining has taken place. It weighs over 500 pounds at 3’x2’ in size. The silver mines in the state of Nevada were uniquely mined in that area found near huge sandstone quarries. The sandstone rock was formed in an ancient inland sea where marine life, including corals, left behind as fossils which were part of the "reefs" of sandstone being mined for silver in the 1950’s and 1960’s where my father managed the silver mines during that time.
