Earth & Space - Materials from Earth - The Earth & its Resources - G15 - ES-D2.3

Learning outcome

Many materials used in building are obtained from the Earth’s crust.

1. These days most houses are built of bricks and tiles which are made from minerals ground up and baked in an oven and from breeze blocks which are made from ash residue left from burning coal, compressed and heated. Houses used to be made of or fronted with stone such as sandstone or granite and marble used to be a common material inside homes - even if it was just a marble slab to keep meat cool.

Playgrounds, roads and pavements have tarmac made with stones and bitumen (an oil product) and some slabs are pieces of original rock. Talcum powder is made from rock and you may use a pumice stone in the bath - that comes from a volcano. Slates are still used on many houses and are mined in several places - Easdale in Argyll, no longer in use, was famed for its slate.

2. Simple rock and mineral guides may give, in detail, the characteristics of certain common rocks such as marble and sandstone.

4. To investigate wearability of rock the children could try rubbing samples of rock on some sandpaper or on another rock but watch for fingers!

Permeable rock is rock which will absorb water. The opposite is impermeable rock. To investigate this, weigh some different rock samples and record their weights. Soak them in water overnight and then dry off the outside with a towel and reweigh. The permeable rock should have absorbed some water and so will weigh more.

5. Rock salt is the mixture put onto the roads to prevent ice forming. It is a mixture of sand and salt and can be bought in bags in the winter. To separate out the salt, the children should be grinding up the granules, dissolving the mixture in warm water then filtering out the sand and leaving the remaining solution in a petri dish to evaporate off the water.

(See P5 Group 13 for more help.)