Corundum (aluminum oxide) can be clear to opaque. The opaque varieties are used as abrasive materials and the clear,like sapphires and rubies,as gems | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Winters, Charles D. |
Taille de l’image : | 3024 px × 2016 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : |
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