Andesite igneous rock specimens of late Ordovician age which form part of the Barrowdale volcanic group. The rocks come from Cumbria, UK and have a dark colouration with a blue tint and may contain augite crystals. The rocks are intermediate in chemistry and suitable for higher level education to explain the difference in various igneous groups. Samples are available in 3 sizes and will come supplied in a card tray with an information label.
Augite andesite igneous rock specimens from Thirlmere, Cumbria, UK which are of late Ordovician age which form part of the Barrowdale volcanic group. The samples are of intermediate composition and contain phenocrysts of the pyroxene mineral, augite, giving the normally dark blue rock a black speckled appearance. The samples are available in 3 sizes and come supplied in a card tray with a label.
Tuff from the Borrowdale Volcanic Group, Ordovician in age, the rock has a green colouration to it and a slate like cleavage, hence sometimes being known as volcanic slate, green slate or Borrowdale slate. Rock specimens are available in 3 optional sizes and will come supplied in a card tray with a label.