Agglomerate. From neck; rhyolitic matrix. Mortonhall Quarry, near Buckstone. The first of c 17,000 photographs of rock specimens from the BGS Systematic Series captured and processed by BGS volunteers in Edinburgh. The Systematic Series is arranged by Geological Survey 1"/1:50,000 map sheet area. Representative rocks from each sheet were collected or drawn from other collections to make a teaching collection for new Survey field geologists.