4.7 x 4.2 x 1.6 cm. So-called "geyserite" is a variety of opal formed in hot springs. Apparently these were collected by a Dr. Leidy in 1877 on a trip, and brought back to give to the Academy for its collections. This piece comes with the original label. NOTE: Collecting in the park is prohibited today. Ex. Philadelphia Academy of Sciences ...
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