Go
back in time, where you had to sluice for your gem stones (yes, and
walk up hill, in the snow, both ways). We have the sluice, the water
and the gems and now all we need is you! You can find such wonderful
gems as amethyst, calcite, pyrite and rose quartz. Rocks are our
livelihood here at the Mark Twain Cave. If it weren't for the rock
called Louisiana Limestone we would not have this wonderful cave! (Ok,
the Mississippi River played a part in the formation, too). Louisiana
Limestone is found only between Hannibal and Louisiana, Missouri; about
a 35-mile stretch. Louisiana limestone is soft limestone, so when the
water seeped in the cracks and crevices, a process called "solution"
occurred and formed the cave as it is today. While the limestone is 325
million years old, the cave itself is only about 10 million years old.
It is speculated that Mark Twain Cave and Cameron Cave were once
connected as one. Then a glacier came through during the Ice Age and
separated the two caves with a valley. That time also brought the
glacial clay that is the "floor" of the cave. So, you see, we love
rocks!
