Sample of chalk. Chalk is a form of soft sedimentary carbonate rock formed from the shells of microscopic marine organisms called coccolithophores | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Trevor Clifford Photography |
Taille de l’image : | 5125 px × 3431 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |