This orange sandstone is made of lots of tiny sugar-like grains of sand. It has a rough texture, similar to a sugar cube. Sandstone is a common building material as it is relatively soft and can be carved easily.

This limestone is a creamy-beige colour and has lots of small bits of fossilised shell inside. Limestone typically forms underwater from sediment building up over long periods of time. Because of this, it is common to find the fossils of sea creatures in limestone, such as ammonites and trilobites.

Flint is very smooth, and can have very sharp edges that make it very useful for making tools like spear heads. This flint is brown and grey with some bits of white on the outside. Flint actually forms inside chalk, another sedimentary rock.

‘Conglomerate’ is a way to describe rocks that are made up of other smaller rocks such as pebbles and grains. If you look closely at this conglomerate, you can see that it is made of grey fragments of rock that are held together by very small red grains.

Chalk is smooth, white and very soft. It is so soft that you can easily scratch the surface with your fingernail and use it to draw with. The White Cliffs of Dover are made out of chalk.

This rock is from one of the most dangerous and active volcanoes in the world, Mount Vesuvius in southern Italy. It has a very rough and uneven texture and is full of holes (pitted). Looking closely you can small shiny black minerals that could be obsidian, an igneous glass. When Mount Vesuvius erupted in AD 79, it destroyed the city of Pompeii.

This piece of obsidian is from Anatolia in Turkey. Obsidian forms when molten rock cools very quickly, forming a volcanic glass instead of a rock. It is usually smooth, shiny and black like this piece in our collection. Obsidian can also be broken to have very sharp edges and was actually used in the Stone Age to make spear heads.

Basalt is a very common igneous rock and is mostly formed by cooling lava, but can also be formed from magma cooling inside the Earth. Our basalt has lots of little holes (pitted) which are formed by gases being trapped as bubbles inside the lava as it cooled into rock.

This pumice is from the Lipari Islands in Italy. Pumice is very light because it is full of so many small holes (pitted). It can float in water and even form giant rafts across oceans. Typically formed in very explosive volcanic eruptions, the holes inside are formed by bubbles of gas.

Porphory is an igneous rock that primary forms inside a volcano, in the magma chamber. Our porphory has black, pink and grey crystals of all different sizes, from small too large.

You can get lots of different types and colours of marble, but the marble in our collection is white with medium sized crystals. The crystals reflect light so that it looks glittery. Limestone changes into marble when put under intense pressure and heat.

This rock has a very strange name that is difficult to say! The correct way to pronounce is without the G and sounds like ‘nice’. Gneiss is one of the oldest type of rocks you can find on Earth. The Gneiss in our collection is grey and shiny, with some pink and black crystals. It is quite hard to see, but this example shows banding - stripes of either black, grey or pink minerals.

Another difficult to pronounce rock name! Try it it without the C, sounds like ‘shist’. This piece of schist is one of our favourite rocks in the collection because it is made up of large dark purple crystals of garnet. It is grey and shiny, and also a favourite amongst students.