Granite. Cut surface of the rock granite,showing its coarsely crystalline structure. The different coloured fragments are crystals of the various mi- nerals that make granite - mostly quartz,feldspar and mica. An igneous rock,granite is formed from molten "magma" (like lava) that rises from deep in the Earth and then cools and solidifies under- ground. Large crystals grow because the magma cools down slowly. The rock's strength makes it an ideal building stone,both polished in slabs for facings,and crushed to make concrete. This 1630 million year old sample is called rapakivi granite. Magnification x0.25 at 35mm size | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Bernard, George |
Bildgröße: | 5003 px × 3579 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |