Corundum is a crystalline form of aluminium oxide (Al2O3) with traces of iron, titanium and chromium. It is a rock-forming mineral. It is one of the naturally clear transparent materials, but can have different colours when impurities are present. Transparent specimens are used as gems, called ruby if red and padparadscha if pink-orange. All other colours are called sapphire, e.g., green sapphire for a green specimen. | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Winters, Charles D. |
Taille de l’image : | 1677 px × 2100 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |