Download Ch. 4 Study Guide Answers

Ch. 4 Study Guide
Section 1
What is a mineral? A naturally occurring, inorganic solid, with a specific chemical composition and a
definite crystalline structure
Name the 5 characteristics of all minerals.
naturally occurring
inorganic
solid
specific chemical composition
definite crystalline structure
Organic vs. inorganic. Organic was once living or came from something that once had life
Why is salt a mineral, but sugar and coal are not? Sugar and coal are organic, salt is inorganic
What is a crystal? A solid in which the atoms are arranged in repeating patterns
What is magma? Molten rock material beneath Earth's surface
When magma cools quickly, small crystals form, and when magma cools slowly, large crystals forms.
Saturated vs. supersaturated solutions. Saturated- completely dissolved. Supersaturated- overfilled
What is an evaporite? Give an example. Minerals that form from the evaporation of liquid. Ex: rock
salt
ID tests for minerals: (Define each)
Crystal form- distinct crystal shape
Luster- the way a mineral reflects light
Hardness- how easily a mineral can be scratched
Cleavage- a mineral that splits easily and evenly along one or more flat planes
Fracture- minerals that break with rough or jagged edges
Streak- the color of a mineral when it is broken up and powdered
Color- the most noticeable characteristic of a mineral
Special properties (I could give you descriptions or pictures for these):
Double refraction- when a ray of light passes through a mineral and is split into two rays
Effervescence- occurs when reaction with hydrochloric acid causes calcite to fizz
Magnetism- occurs between minerals that contain iron
Iridescence- a play of colors, caused by the bending of light rays
Fluorescence- occurs when some minerals are exposed to UV light which causes them to glow
in the dark
Texture- how a mineral feel to the touch
Density- density= mass / volume
Specific gravity- the ratio of the mass of a substance to the mass of an equal volume of water at 4
degrees C
ID tests for minerals are based on their chemical and physical properties.
What are 2 ways we describe luster? Metallic and non-metallic
What is the name of the hardness scale? Mohs scale
What is its range?1-10, 1 being the softest and 10 being the hardest
What is the softest mineral? Talc
What is the hardest mineral? Diamond
Be able to identify a mineral or narrow it down to a range if given the scale and a scenario.
Will all minerals streak? No, a mineral will streak only if it is softer than the streak plate
Color is sometimes caused by the presence of what? Trace elements
Section 2
Which compound is the most abundant in Earth's crust? Silicate
Specifically, it makes up 96% of Earth's crust.
Which elements is it composed of? Oxygen and silicon
What is the name of it's geometric shape? Tetrahedron
Be familiar with carbonates, oxides, sulfides, sulfates, halides, and native elements.
What is an ore? Contains a valuable substance that can be mined for profit
What is a gem? Valuable minerals that are prized for their rarity and beauty
Give 3 examples of a gem. Diamonds, rubies, emeralds, etc.
Ore located deep within Earth's crust are removed by underground mining.
Ores that are near Earth's surface are obtained from open-pit mines.