Agglomerate

Agglomerate is a volcanic rock, sometimes referred to as a pyroclastic rock which is composed of various large sized pieces of volcanic material which can vary depending on the type of volcanic chemistry which produced them. The material is classified as such, when the composition of the rock is at least 75% volcanic bombs, these inclusions will often have a ropy, ragged or ovoid shapes as inclusion in the main body of the material. They are often found in and around volcanic vents and appear to look like breccias of volcanic origin, due to the processes in which they form, agglomerates usually exhibit poor sorting of clasts, with sizes and orientations being random, they will also contain various pieces of igneous rocks embedded within an ash or tuff matrix. As such, they are best described as having a coarse texture and are often fairly hard rocks. These particular specimens belong to the Upper streaky andesite series and come from Glen Coe, Scotland, UK, they are suitable for collectors or higher level education use to further explain various forms of volcanic activity and material ejected. The samples are available in various sizes, each rock specimen will come supplied in a card tray with an information label.