Corundum, an aluminum oxide mineral that is number 9 on the Mohs hardness scale. Gem-quality blue corundum is better known as sapphire. | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Science Source / Charles D. Winters |
Bildgröße: | 4016 px × 2665 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |