geol001

Which of the following is a laboratory method used to map the crystal lattice of minerals? a. X-ray diffraction b. color c. luster d. specific gravity

a. X-ray diffraction

Two physical properties of minerals both result in smooth, flat surfaces with specific angles between them. The first property is externally visible and is the result of how the mineral forms; the second is inherently internal and is the result of breaking a sample of the mineral. These properties are called a. crystal habit and cleavage. b. cleavage and crystal habit. c. cleavage and hardness. d. hardness and cleavage.

a. crystal habit and cleavage.

When you scrape a mineral along a ceramic plate to observe the color of its powder, you are checking the physical property known as a. streak. b. cleavage. c. luster. d. specific gravity

a. streak.

Silicate minerals a. have a silicon-oxygen tetrahedron as their structural unit. b. All of the possible answers are correct. c. are the most common minerals on the Earth. d. are classified by the manner in which the silica tetrahedra are arranged.

b. All of the possible answers are correct.

Which of the following statements about gemstones is true? a. In order to be considered precious or semiprecious, a gemstone must be transparent. b. Many gemstones come from pegmatites, which are particularly coarse-grained igneous rocks. c. A gemstone is a variety of a mineral that has value because of its color. d. Emerald is a gemstone variety of the common mineral corundum.

b. Many gemstones come from pegmatites, which are particularly coarse-grained igneous rocks.

Graphite is a. an ore of lead. b. harder than glass. c. a polymorph of diamond. d. pure silicon.

c. a polymorph of diamond.

Diamonds a. are found in carrot-shaped structures called pegmatites. b. are exceedingly rare, which is why their price is so high. c. are brought from the mantle to the surface in magma that hardens into kimberlite. d. of industrial quality (non-gem quality) have no use and are usually discarded.

c. are brought from the mantle to the surface in magma that hardens into kimberlite.

The tendency of a mineral to break and produce smooth, curving, shell-shaped surfaces is termed a. luster. b. streak. c. conchoidal fracture. d. cleavage.

c. conchoidal fracture.

Crystals a. display asymmetry. b. are youngest in the center and oldest at the outer edge. c. have an orderly internal arrangement of atoms organized in a lattice pattern. d. grow inward from a seed.

c. have an orderly internal arrangement of atoms organized in a lattice pattern.

Which of the following fits the definition of a mineral? a. a lab-grown diamond, because it has a definable chemical composition b. glass, because it's inorganic c. salt, because it's crystalline d. oil, because it's a liquid, not a solid

c. salt, because it's crystalline

Which of the following groups of silicate minerals exhibits a single strong cleavage in one direction? a. single-chain silicates b. independent tetrahedra silicates c. sheet silicates d. framework silicates

c. sheet silicates

The calcite and aragonite minerals that constitute clamshells are examples of which method of mineral formation? a. precipitation from a solution b. solid-state diffusion c. solidification of a melt d. biomineralization

d. biomineralization

The reaction to acid can be an important diagnostic test when identifying minerals. The photo shows a mineral that "fizzes" when an eyedropper is used to apply acid. Which of the following minerals is most likely shown in this photo? a. magnetite b. quartz c. kyanite d. calcite

d. calcite

The crystallization of salt from evaporating seawater a. is, in mineralogic terms, formation of a silicate mineral. b. results in hexagonal, prismatic crystals. c. takes place when the solution becomes undersaturated. d. is an example of precipitation from a solution.

d. is an example of precipitation from a solution.

Which of the following is a mineral? a. glass b. amber (tree sap) c. sugar (C6H12O6) d. oyster shell (CaCO3)

d. oyster shell

An unknown mineral scratches glass, has only average specific gravity, and shows no cleavage but does show conchoidal fracture. Which of the following could it be? a. talc b. halite c. mica d. quartz

d. quartz

The great varieties of minerals on the Earth are classified by mineralogists into a small number of groups on the basis of a. their color. b. their crystal habit. c. the manner in which they form. d. the negative ion or ionic group in their chemical composition.

d. the negative ion or ionic group in their chemical composition.