Quartz monzonite is an intrusive igneous rock which is felsic in classification. It is suggested that monzonites have an equal proportion of the two major feldspar minerals, orthoclase and plagioclase and is generally a coarse grain texture rock. As the name suggests, quartz is also present in large quantities as well as dark minerals often associated with igneous activity such as biotite and hornblende. Similar in composition to granites, the levels of quartz differentiate this rock from the granitic group, where a rock has above 20% of quatrtz, it is classified as a granite, between 5% - 20% and it is classified as a monzonite. These particular rock specimens come from Ratagan, Glen Shiel, Scotland and is available in various sizes to choose from, each piece is supplied in a card tray with an information label.