Cut and polished agate. This agate formed following precipitation of chalcedony (coloured) and quartz (white) inside cracks or voids in a rock. Both are forms of silica. The coloured parts are tinted by impurities of some metallic element,like copper or iron. Although the chalcedony is non-crystalline,it has precipitated in a semi-crystalline dendritic (branch-like) pattern | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Wiersma, Dirk |
Taille de l’image : | 5242 px × 3770 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |