Characteristics of Minerals

Color
Minerals have a huge viarity of colors, blue, red green, orange, yellow and even colorless. Even though their beautiful colors, it is not good to identify minerals by their color because many minerals can have that same color. In this picture you can see many colorful minerals.

Streak

The streak is the powder a mineral lefts when it is scratch. Scientists can use the color of the streak to identify a mineral but it is really hard. Many minerals have the color of its streak like pyrite but many others have a different color in their streak like Cinnabar.

Luster

Luster describes how light is reflected in a mineral. There are nine types of lusters, these are, earthy, waxy, pearly, glassy, metallic, greasy, dull or submetallic and silky. For example, quartz has a glassy luster, galena has a metallic luster, graphite has a greasy luster, gypsum alabaster has a waxy luster, talc has a dull or submetallic luster.

Density

Density means mass divided by volume. The size doesnt matter because some smaller minerals are denser that some that are bigger. Dense is a good way to identify a mineral because each mineral has its own density. Galena is a very dense mineral, it has a density of 7.4g/ccm.

Hardness

Hardness is the ability of a mineral to resist being scratched. There are the diferent steps to measure hardness in the Mohs scale, diamond is the hardest.
Mohs hardness
Mineral
1
Talc (Mg3Si4O10(OH)2)
2
Gypsum (CaSO4·2H2O)
3
Calcite (CaCO3)
4
Fluorite (CaF2)
5
Apatite (Ca5(PO4)3(OH-,Cl-,F-)
6
Feldspar (KAlSi3O8)
7
Quartz (SiO2)
8
Topaz (Al2SiO4(OH-,F-)2)
9
Corundum (Al2O3)
10
Diamond (C)

Crystal System

The crystal system of a mineral is the structure formed given by the number of sides and the angles in a crystal. There are six types of crystal systems, isometric or cubic, tetragonal, hexagonal, orthorombic, monoclinic and triclinic. Halite has a cubic or isometric crystal system.

Cleavage or Fracture

Fracture is the formed left when a mineral splits irregulary. Cleavage is when a mineral can split into flat surfaces. this is because of its atoms. For example Mica has cleavage and