L1 /
3
CH3041
ROCK SCIENCE
• Rock: a
solid, cohesive mass of pure
mineral or several minerals.
mineral or several minerals.
• Mineral: a
naturally occurring inorganic solid with a definite internal crystal structure and chemical
composition.
• Minerals may crystallize in more than one crystal
form. Each form has a different internal structure and different
physical properties colour, hardness, etc.
eg a-quartz trigonal crystals, b-quartz hexagonal
eg a-quartz trigonal crystals, b-quartz hexagonal
• Primary minerals form by crystallisation during
cooling of the magma. eg. quartz
• Secondary minerals form by alteration of
parent minerals at the surface. eg. clays
• The crust
is formed principally from
25 rock-forming minerals.
25 rock-forming minerals.
