Sapphire crystal. Sapphire is a blue variety of corundum (aluminium oxide), the second hardest known mineral. Specimen from Olberg, Rheinland, Germany

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Sapphire crystal. Sapphire is a blue variety of corundum (aluminium oxide), the second hardest known mineral. Specimen from Olberg, Rheinland, Germany.

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Size: 2944px × 2968px
Photo credit: © NATURAL HISTORY MUSEUM, LONDON/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

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