All our rocks are carefully selected for educational study. They come in labelled trays. The trays are normally 3″ x 2″ size depending on the rarity of the specimen. Average specimen size is shown below. These are ideal for classroom teaching and are a size that can be easily passed round the classroom for students to get a feel for each type.
Granite is a very hard, granular, crystalline igneous rock which consists mainly of quartz, mica, and feldspar and is often used as building stone
Microgranite is the medium-grained equivalent of granite. The crystals are slightly smaller than granite indicating that the magma cooled more quickly. It usually occurs in smaller intrusions than granite. Microgranite forms from magma that contains a lot of quartz (silica).