Description
Gypsum (selenite) crystals from Montmartre, Paris, France.
The two crystals are loose, shock-free and quite translucent.
Many gypsum quarries were still being exploited in Montmartre in the 19th century, this mineral being the raw material for plaster (the famous plaster of Paris).
Old specimens from the mineral collection of the Philadelphia Academy of Sciences.
They are accompanied by the original box and handwritten labels.
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