Chard flint with a ruler (right) indicating scale in millimetres. These large,smooth stones can be up to 20 millimetres in length and are used as the aggregate in concrete | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Hart-Davis, Adam |
Bildgröße: | 4545 px × 3852 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |