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 | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Wiersma, Dirk |
Taille de l’image : | 5071 px × 3446 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |