Opal gem and opal rock. Polished and rough specimens of opal,a form of hydrous silicon oxide (silica,SiO2). When cut and polished,it has a distinctive blue iridescent sheen. The rough specimen comes from Baracoo River,Queensland,Australia | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Natural History Museum, London |
Taille de l’image : | 4698 px × 3720 px |
Model Release : | Non requis |
Restrictions : | - |