This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
The Quarterly journal of the Geological Society of London . PROCEEDINGS OP THE GEOLOGICAL SOCIETY Juiie The author then describes the occurrence of gold in the Lower Silurian rocks It is found disseminated in small foliaceous particles or in round grains in the quartzveins which traverse the greywacke sandstone and shale in