Opal specimen and cut stone. Opals are a form of hydrated silica glass. They are not truly crystalline,and are classified as mineraloids | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Natural History Museum, London |
Bildgröße: | 3764 px × 4642 px |
Modell-Rechte: | nicht erforderlich |
Restrictions: | - |