There are some facts one may think he knows in Geology but…oops! They are really obfuscating. The look so elementary that they are easily jettisoned.
A Rock is an aggregate of naturally occurring minerals.
A Mineral is an inorganic, crystalline and naturally occurring substance with a definite chemical composition.
Physical Properties of Minerals
- Hardness (measured in Mohs Hardness Scale). It increases downwards.
- Luster: is the manner the mineral reflects light.
- Color: each mineral has its basic colour for which it is known. But this is usually deceptive.
- Streak: The color of the mineral in powdered form.
- Cleavage: How the Mineral breaks along its plane of weakness.
- Fracture: How the mineral breaks unevenly.