Materials

Marble is limestone that has been changed from a sedimentary rock to a crystalline one through high pressures under the surface of the Earth. Marble is much stronger than limestone, and can be polished to a shiny finish. It is frequently used for making statues from, and for making decorative features in buildings like floors and pillars from.

Mercury, also called quicksilver, is the only metal that is liquid at room temperature. Mercury is a heavy metal and is very toxic.
Mercury is used to dissolve gold in the process of gold mining, it was used in making felt, in older style thermometers, and in dental fillings.

There are many different kinds of metal. The metals that are used in everyday life are hard, usually shiny, and smooth. Metals are good conducters, which means they can change temperature very fast. If you stir some hot water with a metal spoon for too long you can burn your fingers as the spoon heats up.
Most metal is soft enough to be bent into interesting shapes, although for very thick metal it can take a lot of force to bend it. Some metal, like the kind that goes into knife blades, is hardened and can't be bent.

Moonstone is a mineral made from potassium aluminium silicate. It is formed in thin layers, which gives it an interesting light scattering effect called adularescence. The highest quality moonstones come from Sri Lanka.

Mother of pearl is a very hard, attractive substance that is is frequently used in jewellery or as inlays on furniture, wooden boxes or even the handles of guns. Mother of pearl, or nacre, is the iridescent material lining the shells of some sea molluscs, which includes snails, clams and other shellfish.
Most commonly, mother of pearl was used for centuries to make buttons from.

A net is a type of fabric woven into a grid of large holes. Nets are designed to let small things or liquids go through, and catch larger things. Nets are very commonly used to catch fish and butterflies, and to keep birds away from fruit trees.

Oak is timber from the oak tree. It can be used to make floors and furniture.

Olivine is a common olive green mineral made up of magnesium iron silicate. It has also been found in asteroids and on the moon. Olivine can be quite brittle. When olivine is transparent and gem quality, is is called peridot.

Opal is not a true mineral, but a crystalline gel made up of spheres of silicon dioxide and water. The pattern of the spheres makes opal refract light into lots of different colours, with blue and green being the most common. Opal is used often in jewelry, and is the national stone of Australia.

Paraffin is the name given to a range of fuel oils, also called kerosene in some countries. The form of paraffin most people are familiar with is paraffin wax, which is used to make candles from.