GRANITE |
Type of Rock: | Magma: | Texture: | Mineralogy: |
Igneous rock | Intrusive (doesn't reach the surface) cool at low temperatures. | Phaneritic (coarse grained) | Granite crystallizes from silicate minerals at relatively low temperatures and with relatively high percentage of silica is generally referred to as "felsic" rock. Predominant minerals : potasium feldspar and quartz. |
THIN SECTION A thin section is made by grinding down a slice of rock which has been glued to a glass slide until it reaches a thickness of about 0.03mm (30 microns). At this thickness most minerals become more or less transparent and can therefore be studied by a microscope using transmitted light. |
© Guillermo Rocha, P. G. / Brooklyn College Geology Department