Chapter 3 quiz & hw

q13: Which of the following statements about hardness is true? A. A copper penny will scratch gypsum. B. Calcite will scratch fluorite. C. Apatite is harder than orthoclase. D. Diamond has a Mohs hardness of 10 because it is 10 times harder than talc (hardness of 1).

A copper penny will scratch gypsum

q17: Silicate minerals -are classified by the manner in which the silica tetrahedra are arranged. -are the most common minerals on the Earth. -have a silicon-oxygen tetrahedron as their structural unit

All of the possible answers are correct

q19: Which of the following statements about gemstones is true? A. Emerald is a gemstone variety of the common mineral corundum. 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. In order to be considered precious or semiprecious, a gemstone must be transparent.

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

h2: Obsidian is a volcanic glass that forms when lava cools very quickly and consists of a solid mass of glass through and through. Why is obsidian not classified as a mineral?

The atoms or molecules in obsidian do not have a crystalline structure

h3:What would be the significance of finding a precipitated mineral on another planet?

The planet may have or have had liquid water on it.

h8: Gems like this diamond have smooth, reflective faces called facets. Which of the following best describes the origin of these surfaces?

They are produced by grinding and polishing

q8: Which of the following is a laboratory method used to map the crystal lattice of minerals? A. luster B. X-ray diffraction C. color D. specific gravity

X-ray diffraction

q7: Graphite is

a polymorph of diamond

q20: Diamonds

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

q5: The calcite and aragonite minerals that constitute clamshells are examples of which method of mineral formation?

biomineralization

h5: Label the types of minerals and their corresponding types of fractures. The leader lines indicate fractures.

brown: garnet w/ irregular features white: quartz w/ conchodial features

h9: Given that a mineral has three planes of cleavage, one of which is inclined, and breaks into rhombs, is the mineral mica, pyroxene, amphibole, halite, or calcite?

calcite

q14: 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?

calcite

q9: The tendency of a mineral to break and produce smooth, curving, shell-shaped surfaces is termed

conchoidal fracture.

q3: Which type of chemical bond occurs when atoms share electrons, as shown in this diagram?

covalent

q10: 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

crystal habit and cleavage.

h12:Which type of silicate has the greatest proportion of oxygen atoms shared by pairs of adjacent tetrahedra?

framework silicates

q6: Crystals

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

q4: The crystallization of salt from evaporating seawater

is an example of precipitation from a solution

h10: The hardness of a mineral is determined by

its ability to resist being scratched by other substances.

h11: Label the atoms in the silica-oxygen tetrahedron shown in the image below. The silica-oxygen tetrahedra is the building block of which chemical class of minerals?

middle: silicon outside: oxygen silicates

h1:Identify the following substances as mineral, mineral simulant, or non-mineral.

mineral: - aragonite -gypsum -graphite -corundum mineral sumulant: -cubic zirconia -hematine non-mineral: -DNA -menthol -glass -sugar

q1: Which of the following is a mineral? A. glass B. sugar (C6H12O6) C. amber (tree sap) D. oyster shell (CaCO3)

oyster shell (CaCO3)

q11: 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?

quartz

q2: Which of the following fits the definition of a mineral? A. salt, because it's crystalline B. glass, because it's inorganic C. a lab-grown diamond, because it has a definable chemical composition D. oil, because it's a liquid, not a solid

salt, because it's crystalline

q18: Which of the following groups of silicate minerals exhibits a single strong cleavage in one direction? A. sheet silicates B. independent tetrahedra silicates C. framework silicates D. single-chain silicates

sheet silicates

q12: When you scrape a mineral along a ceramic plate to observe the color of its powder, you are checking the physical property known as

streak.

q16: The great varieties of minerals on the Earth are classified by mineralogists into a small number of groups on the basis of

the negative ion or ionic group in their chemical composition

h7: Which of the following best describes the number and orientation of cleavage directions in this mineral? A. two cleavage directions at 90° B. three cleavage directions not at 90° C. three cleavage directions at 90° D. two cleavage directions not at 90°E. one cleavage direction

three cleavage directions not at 90°

q15: If you smashed a piece of halite (table salt) with a hammer and broke it into smaller pieces, the broken crystals would look like cubes, as seen in the image. This is because halite has

three planes of cleavage that intersect at 90°

h6: Match the adjectives for luster with the appropriate specimen.

top to bottom: glassy metallic earthy

h4:Crystals come in a variety of shapes; each shape has a geometric name. Based on the descriptions provided of representative minerals, match the mineral name to the corresponding mineral image.

white rectangle prism: calcite yellow: fluorite white pentagon: quartz red: garnet green cube: halite