Carrstone is the name given to an iron oxide rich variation of sandstone (known as ferruginous). It is easily identifiable due to having a deep, rusty red colouration and a very weak,friable rock texture. The colour becomes present in this sedimentary rock by leaching processes, which occur in irregular veins and is commonly a dark orange brown. At one time it was used as a source of iron ore in Surrey (Abinger Hammer) and today may be seen on old buildings, where it was used as a facing stone. However, the weak properties of this rock mean that it cannot be used for much else. These samples are Cretaceous in age, making them between 145 to 66 million years old and were found in the Lower Greensand formations of Westcott, Surrey in the UK. Specimens are available in various sizes and come supplied in a card tray with an information label. Due to the fragile nature of this rock, care is recommended when storing and handling them.