Located in South Dakota, it was established on this date in 1908.
It is the third longest cave system in the world; with over 208 miles of mapped and surveyed passages.
Jewel Cave was formed by the gradual dissolution of limestone by acid-rich water. The water enlarged a network of cracks formed during the uplift of the Black Hills roughly 60 million years ago. The layer of calcite crystals that covers much of the cave walls was created by the re-deposition of calcite from water saturated with the mineral.
After the water drained, speleothems (cave formations) began to form. Jewel Cave contains all the common types of calcite formations such as stalactites, stalagmites, flowstone and frostwork.
The dry parts of the cave contain some formations created by the deposition of gypsum such as gypsum needles, beards, flowers and spiders.
Finally, Jewel Cave contains a very rare formation called a hydromagnesite balloon. Those are created when gas of an unknown source inflates a pasty substance formed by the precipitation of the magnesium carbonate hydroxide mineral.
This page is a permanent link to the reply below and its nested replies. See all post replies »
I happened upon it many years ago on a family vacation. It was amazing! We've been in a fair number of caverns, but this one is completely unique and memorable.
@sciguy18 Yes, purely by accident, seeing the sign along the road. It is spectacular. At one point they had the lights off and shown flashlights around. The walls shone like diamonds.
Another amazing find was the Cody Museum in Cody Wyoming.
