Synthetic spinel. This is the magnesium-aluminium member of the spinel group of minerals. Synthetic spinel was first produced accidentally during an attempt in the 18th century to make a satisfactory blue synthetic sapphire by the Verneuil process. In this process natural spinel of low purity is ground to a fine powder and melted under very high temperature to form,upon solidification,a synthetic variety of high purity. This specimen measures 200 millimetres across | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Wiersma, Dirk |
Bildgröße: | 5071 px × 3446 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |