Name________________________________ Date__________________________ Period ___________
Minerals
Define the following terms. Put a check mark before the term when you are sure you
know the definition.
Mineral - is a solid, naturally-occurring object with a defined chemical composition,
inorganic, crystalline structure
cleavage plane – a flat surface along which minerals easily break
Mohs Hardness Scale – a ranking of minerals based on their resistance to scratching
Answer the following questions:
1. Name 9 properties of minerals used in identification. Explain each.
Examples: color, streak, hardness, fracture, cleavage, luster, fluorescence, taste,
smell, reactivity
Be able to describe the process of identifying a mineral (like in the lab)
2, What is the hardest mineral on Mohs hardness scale? The softest?
Softest – talc
Hardest - Diamond
3. If a mineral is scratched by a nail but not by my fingernail, what can you say about its
hardness?
Hardness between 2 and 4
4. How could you easily identify halite?
Halite has a salty taste (but not in lab).
5. How could you easily identify calcite?
Calcite reacts with water.
6. What is the most common mineral in the Earth’s crust?
Quartz
7. How many minerals make up the Earth’s crust?
About 3,000
8. Explain why it is sometimes hard to identify minerals?
Some minerals have similar colors, hardness and other physical properties,
therefore it is difficult to tell those minerals apart.
9. Explain what it means for mineral to have fluorescence.
The minerals glow under a black light (UV light)
Rocks
Define the following terms. Put a check mark before the term when you are sure you
know the definition.
Magma – melted rock underneath the surface of the earth
Lava – melted rock on the surface of the earth
Sedimentary Rock – rock formed by cementing, compaction or crystallization of minerals
Igneous Rock – rock formed by cooling of lava or magma
Metamorphic Rock – rock formed from existing rock exposed to high heat and pressure
causing a change in the structure of the rock
Mafic – dark colored rocks (because they contain dark colored minerals such as iron)
Felsic – light colored rocks (because they contain light colored minerals such as quartz)
Rock Cycle – be able to draw the rock cycle
Foliation – found in metamorphic rock, minerals arranged in bands or planes
Banding – alternating light and dark bands in the rock
Rock Cleavage – a rock breaks cleanly at a surface
Contact Metamorphism – metamorphism as a result of contact with magma
Regional Metamorphism – metamorphism that occurs over a large area, the result of the
pressure of the Earth’s crust and higher temperatures in the mantle.
Answer the following:
1. How are igneous rocks formed?
Rock is melted below the surface of the earth. The melted rock (magma) cools
either below the surface of the earth (intrusive) or above the surface of the earth
(extrusive).
2. What is the difference in the way an intrusive and an extrusive igneous rock form?
Intrusive rocks cool slowly, below the surface of the earth, resulting in large
mineral crystals (course textured rocks). Extrusive igneous rocks cool quickly, above the
surface of the Earth, giving them a fine-grained or glassy texture (also frothy in some
cases).
3. What is the most common igneous rock?
Granite
4. What is the glass volcanic igneous rock called?
Obsidian
5. Name a frothy igneous rock.
Pumice, scoria
6. What are the three formation methods for sedimentary rocks?
Compaction (rocks are crushed together, sticking together forming a larger, mostly
homogenous rock)
Cementation (rock pieces are held together with a matrix – usually a fine clay or silt
mixture)
7. What is a fossil and what type of rock would we see them in?
A fossil is the remains of a living organism. These are found most often in
sedimentary rock (because the sediment will settle and compact around the fossil).
8. What is the difference between a conglomerate and a breccia?
Conglomerates have rounded edges to the clast pieces whereas breccia have angled
larger pieces of rock in the matrix.
9. What are the controlling factors on metamorphism?
Temperature and pressure control the process of metamorphism.
10. Describe what can happen to the minerals in a rock when it undergoes metamorphism.
As existing rocks/minerals are exposed to high heat and pressure under the
surface of the earth, the minerals will often align together and create bands of different
minerals in the metamorphic rock.
11. What is the difference between contact and regional metamorphism?
- Contact metamorphism happens with rock is in direct contact with magma.
- Regional metamorphism happens when rock is buried far enough under the surface
to temperature and pressure to change the structure.
12. Draw a flowchart of the rock cycle. Explain the rock cycle.
13. What is the difference between a rock and a mineral?
Minerals are inorganic solids, with a definite chemical composition and structure.
Rocks are combinations of different minerals. Rocks do not have a definite composition
(they have definite components, but percent of each mineral is not always the same).
Rocks may contain both organic and inorganic parts.
14. Explain what happens to the characteristics of minerals when rocks are formed.
The minerals are mixed together in a physical combination. The chemical structure
of the mineral stays the same, so the characteristics of the mineral remain, though they
may be difficult to detect in fine-grained rocks.