Introduction to Earth Science

Introduction to Earth Science

Quiz 2 - Basic Geologic Principles

1. A rock is a:
a) a mixture.
b) composed of one or more minerals.
c) may include non-mineral substances, such as water, gases, or organic matter.
d) all of the above.

2. A substance that in considered a mineral must have which of the following characteristics:
a) It must be naturally occurring in the environment.
b) It must be an inorganic (never living) solid.
c) It must have crystal structure with a definite internal arrangement of atoms.
d) all of the above.

3. What are the three types of rocks?
a) igneous, sedimentary, and metamorphic.
b) minerals, soils, and rocks.
c) weathering, transportation, and deposition.
d) igneous, sedimentary, and molten.

4. What two elements are most abundant in the Earth’s crust?
a) hydrogen and oxygen.
b) oxygen and silicon.
c) carbon and silicon.
d) iron and aluminum.

5. Very few things that are solid are not crystalline. Most naturally occurring, inorganic materials are crystalline substances, having the structure and form of a crystal or is composed of crystals. What is an example of a material that is not a crystalline substance?
a) glass.
b) halite.
c) fluorite.
d) none of the above.

6. Roughly, about how many atoms are in a single crystal grain of salt?
a) 1.2 x 106 (or 1,200,000)
b) 4.5 x 109 (or 4,500,000,000)
c) 13.8 x 109 (or 13,800,000,000)
d) 1.2 x 1018 (or 1,200,000,000,000,000,000)

7. A crystal structure describes a highly ordered, repeatable arrangement of atoms. Only when molecules are arranged in an orderly, repeatable symmetric pattern will it be considered a mineral. The simplest possible representation of molecule to for a crystal structure is called:
a) a mineral.
b) a unit cell.
c) an octagon.
d) a chemical formula.

8. A mineral with the chemical formula of CaCO3 and has a hexagonal or trigonal crystal shape is:
a) dolomite.
b) calcite.
c) quartz.
d) gypsum.

9. Which crystal system has crystal shapes that have symmetry axes in equal lengths in 3 directions (at 90º angles to each other) are part of the:
a) trigonal crystal system.
b) isometric crystal system.
c) tetragonal crystal system.
d) triclinic crystal system.

10. The tendency of a crystallized substance (including minerals) to split along definite crystalline planes, yielding smooth surfaces is called:
a) non crystalline.
b) chatoyancy.
c) luster.
d) cleavage.

11. The description of the quality and intensity (sheen or shine) of light reflected off of a mineral, particularly a reflective appearance of the exterior of crystal surfaces is called:
a) luster.
b) fluorescence.
c) specific gravity.
d) double refraction.

12. A mineral that can transmit light, but it is dispersed or cloudy is called:
a) opaque.
b) transparent.
c) translucent.
d) all of the above.

13. "Iceland spar" is a mineral that can demonstrate double refraction—that is, light passing through clear iceland spar will transmit a double image, or split a laser beam into two separate beams. Iceland spar is a variety of what mineral?
a) quartz.
b) calcite.
c) feldspar.
d) mica.

14. According to the Mohs Hardness Scale, which is the hardest mineral?
a) quartz.
b) topaz.
c) diamond.
d) feldspar.

15. Many rocks contain minerals that are rich in iron and are partly magnetic and display measurable magnetic susceptibility -- making them useful for geophysical exploration, such as finding hidden faults or mineral ore bodies. A mineral with high magnetic susceptibility includes:
a) magnetite.
b) calcite.
c) diamond.
d) labradorite.

16. The property of a mineral to glow in often bright colors when exposed to invisible ultraviolet radiation (glow under a blacklight) is called:
a) schiller.
b) fluorescence..
c) phosphorescence.
d) thermoluminescence.

17. A geiger counter is used to:
a) count the potential facets on a crystal.
b) count the number of elements in a mineral.
c) measure levels of radioactivity.
d) measure the amount of electricity to move through a rock or mineral.

18. Examples of sheet silicate minerals include:
a) mica
b) biotite
c) muscovite
d) clay minerals
e) all of the above.

19. The minerals orthoclase and plagioclase are examples of what common group of minerals?
a) quartz.
b) feldspars.
c) micas.
d) mafic silicate minerals.

20. Mafic silicate minerals are rich in magnesium and iron. The word mafic is used to describe rocks containing a group of dark-colored, mainly ferromagnesian minerals (rich in iron and magnesium). Mafic rocks are common in the Earth's crust under the ocean basins and are exposed in the volcanoes of Hawaii and Iceland. Two examples of mafic minerals include:
a) calcite and dolomite.
b) quartz and feldspar.
c) biotite and muscovite.
d) pyroxene and olivine.