Mineral Properties Flashcards
A natural substance with distinctive physical and chemical properties, composition, and atomic structure.
Minerals
What is the 4 part definition of a mineral ?
Naturally occurring.
Inorganic substance.
Crystalline solid.
Definite chemical composition.
What do you call substances that meet three of the four criteria?
Mineralloids
What is an example of a mineraloid?
Opal, because it doesn’t have an orderly arrangement of atoms
How many minerals are there?
There are 3500 known minerals in the Earth’s crust.
How are all rocks on earth formed?
Minerals combine to form ALL rocks
What does rock type depend on?
Mineral Composition
How many minerals combine to form most rocks on earth?
20 minerals combine to form 95% of all rocks on earth
Minerals have at least this many physical properties that can be used to define or describe, or identify them.
How many and can you name them?
There are 8 main properties: Color, Luster, Streak, Hardness, External Crystal Form, Cleavage, Fracture, Specific Gravity
(Apparently Density is part but it’s not in the powerpoint.)
Do all minerals have some color?
Yes, and some are found in multiple colors
Would you use just a color to define a mineral?
It would be helpful and distinctive, but it can also be very ambiguous
Name the types of Luster.
Glassy, Metallic
(Apparently Dull is part but it’s not in the powerpoint.)
Type of Luster that reflects light like a piece of glass
Glass/Glassy
Type of Luster that Reflects light like a piece of metal would
Metallic
How can the streak color be important? In other words, how can using streak be better to identify a mineral than just a minerals color?
The color could be different from the crystals, actual color, and is always distinctive. (it is not ambiguous like just the crystals color.)
The scratch-ability of a mineral, or a minerals durability
Hardness
Which scale do you use to measure hardness? Describe how things are measured.
Moh’s scale
It is measured on a system of 1-10
1 = very soft.
10 = hardest substance known to man
Streak plate has a hardness of _____
7
A set of faces that have a definite geometric relationship and shape
Crystal Shape/ External Crystal Form/ Crystal Systems
Three axes of equal length, all axes at right angles to each other.
Isometric
Three axes, two equal length, third is longer
All axes at right angles to each other.
Tetragonal
Three equal axes in the same plane
Intersect at angles
