intro to minerals 1 .pptx - Minerals What is a Mineral? •...

Minerals

What is a Mineral?

Only a few elements make up most
of the earth’s crust

Physical properties: Atom
Arrangement
•
some properties are determined by the orderly arrangement of
atoms.
•
The orderly arrangement of atoms in a repeating pattern makes a
mineral crystalline
•
The arrangement also determines how the mineral breaks, how hard
it is, and its crystal shape

Physical properties: how minerals
break
•
Cleavage: when mineral s break along planes of weak chemical bonds,
a smooth flat surface is created
•
All parallel cleavage planes define a single direction of cleavage
•
Some minerals, (such as Micah), have only one direction of cleavage
•
Other minerals can have multiple directions of cleavage that meet at
various angles
•
Fracture: an irregular or uneven break that occurs when minerals do
not split along well-defined, flat surfaces (Quartz fractures, does not
cleave)