Crystal Cave , Ohio - United State

The Crystal Cave is a limestone cave located in Put-in-Bay, Ohio,located on South Bass Island in Lake Erie, It is also the world's largest known geode.

In 1887 a Mr. Gustav Heineman emigrated from Baden-Baden, Germany to Put-in-Bay, Ohio, where he established a winery. In 1897 he dug a well beneath his winery and discovered a large vug at a depth of 30 feet (10 m). On exploring the cave he found the cave walls covered with extremely large and well-developed tabular crystals identified as celestine, a form of strontium sulfate.

The original cave was much smaller than it is today, as much of the celestite was mined for the manufacturing of fireworks. However, Mr. Heineman decided to stop the mining and turn the property into a tourist attraction. Due to the Crystal Cave, the Heineman winery survived prohibition because of tourist revenues.
Today the Crystal Cave is open daily, where celestine crystals of up to 3 feet (1 m) in width can be viewed. The crystals form extensive linings on the limestone walls of the 30 foot (10 m) deep cave.
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