Earth Science 9B Quiz

What is a mineral's cleavage related to?

- how its atoms are arranged in the crystal - to the strength of the chemical bonds between them

What are conditions under which accretion can happen?

- in water with lots of dissolved pure substances - in cooling magma - as hot gases of pure substances cool near a volcano vent

Why is observing a sample's color not as easy as it sounds?

- many minerals have similar colors - some minerals change colors when exposed to air because they chemically react with water vapor, oxygen, or some other chemical in the air - impurities can give samples of the same mineral different colors

Mineralogists have identified about ______ classes of mineral crystals.

32

Why do geologists study minerals?

Geologists study minerals to better understand where they came from through identification, classification, and analyzing.

What are minerals with a metallic luster?

Gold, silver, and copper

What is a mineral with low specific gravities? What is a dense mineral with high specific gravities?

Gypsum; Gold

What happens during accretion?

The minerals grow larger. Atoms or ions add one-by-one to the existing crystal structure

The process by which a crystal grows is called _?_.

accretion

What mineral represents a triclinic mineral system?

axinite

The way that a mineral breaks into sheets is called its _?_.

cleavage

The way a mineral breaks into uneven surfaces is known as its _?_.

fracture

What type of mineral breakage is pictured below? - A mineral has/was broken into uneven surfaces

fracture

What are other recognized lusters beside glassy/vitreous, pearly, adamantine, and silky?

greasy, waxy, earthy (or dull), and resinous

The Mohs scale is a measure of a mineral's _?_.

hardness

_?_ is also a property of some minerals. (shiny rocks are on a shelf)

luminescence

The way that a mineral reflects light from its surface is its _?_.

luster

Minerals that contain iron are _____. Minerals that contain other metals like copper or aluminum are ________.

magnetic; nonmagnetic

What is the best example of a magnetic mineral?

magnetite

Minerals can have either a ____ luster or _______ luster.

metallic; nonmetallic

What mineral represents an orthorhombic mineral system?

olivine

What mineral represents a monoclinic mineral system?

orthoclase feldspar

What mineral represents a cubic mineral system?

pyrite

The ratio of a mineral's density to water's density is called the mineral's _?_.

specific gravity

The color of a mineral's powder is called its _?_.

streak

Fracture

the characteristic manner in which some minerals break; a property of minerals used for identification.

How do mineralogists produce the powder of a mineral when the mineral is harder than a streak plate?

the mineralogists rasps the mineral with a file or other tool to produce powder

Specific gravity

the ratio of a mineral's density to the density of water at 4 degrees C; it's used for identification

Antimagnetic minerals

they weaken a magnetic field when placed in one

True or False: A mineral rated as 1 on the hardness scale is hard.

False

True or False: A mineral's color is more reliable for identification than its streak.

False

True or False: All minerals produce a streak.

False

True or False: There are six basic mineral systems related to crystal shapes.

False

True or False: To find the density of an object, multiply the mass by the volume.

False

True or False: When you conduct an acid test on a mineral sample, you are watching for a color change.

False

What are examples of minerals who show a perfect rating for cleavage and a none rating for cleavage?

Mica - perfect rating Quartz - shatter + don't show cleavage at all

What is test during a streak plate test?

Mineralogists normally test a mineral's streak by using a streak plate.

What do you call the work of conducting various tests such as conducting tests on mineral samples, weighing them, testing them with certain chemicals, etc. Who are the people who do these things?

Mineralogy; mineralogists

Cleavage

Minerals split into flat sheets or along certain planes, creating new facets

What are examples of minerals that can alternate color due to their reaction to air, impurities, etc.? What colors can they be?

Quartz - green, pink, blue, white, or dark gray Amethyst - quartz with manganese impurities that make it violet Corundum - colorless, but when chromium is present, turns a shade of red and forms a ruby

What is the purpose of using a flame test to identify minerals?

Some minerals produce characteristic colors of flame when they burn which is what mineralogists want to analyze and observe.

Who lived shortly after the time of Christ and was one of the first people to describe mineral crystals? What did he note?

The Roman philosopher Pliny noted that mineral crystals come in many fascinating shapes and sizes. From microscopic to huge crystals that weigh several tons.

Why are bubbles of gas produced when hydrochloric acid is put onto minerals such as carbonates, sulfides, and sulfites.

The acid reacts with the mineral, just as baking soda fizzes when you it with vinegar, which is also an acid.

(True or False): The Mohs Hardness scale gives the relative hardness of minerals in comparison to each other.

True

True or False: A crystal face is called a facet.

True

True or False: A mineral's crystal classification deals mostly with its shape.

True

True or False: A person can become good at estimating whether a mineral's specific gravity is low, average, or high.

True

True or False: Cleavage also involves the number of directions in which a mineral breaks.

True

True or False: Each mineral tends to form distinctive crystals with characteristic faces, called facets.

True

True or False: Even though the color of a specimen can vary because of impurities, its streak is the same color in any case.

True

True or False: If a mineral is harder than the streak plate ceramic, then you won't be able to create a mineral powdered streak.

True

True or False: Mineralogists usually have to do more than one test on a mineral to determine its identity.

True

True or False: Scientists further categorize nonmetallic luster on the basis of the appearance of the sample. Because of this, determining nonmetallic luster is more challenging.

True

True or False: The numbers of the Mohs scale show only their relative order of hardness, not their actual hardness as measured by special instruments.

True

True or False: The position of the facets around the center of the crystal determines the symmetry of the crystal.

True

True or False: Through impurities can make it hard to identify a mineral, they can also affect is value.

True

True or False: When they have room, crystals build a shape based on the arrangement of atoms in the mineral.

True

Pictured below is the type of test used to identify carbonates, sulfides, and sulfites. What type of test is it?

acid test

What test would you do to see whether a mineral has carbonate, sulfide, or sulfite in it?

acid test

If you connect the center point of a facet to the center of the crystal with an imaginary line, you create a(n) _________.

axis of symmetry

What mineral represents a hexagonal mineral system?

beryl

How do you produce a streak of powder for most minerals?

by rubbing a surface with a sample - this is appropriately called a mineral's streak test

Which property of mineral identification is shown below? - A knife is being used to test the mineral's breakage into sheets

cleavage

What are the two ways in which a mineral can break?

cleavage and fracture

The specific gravity of a substance is simply the number value of its ______.

density

What mineral represents a trigonal mineral system?

dolomite

What are five common objects that can be used to estimate a mineral's hardness?

fingernail, copper coin, glass, knife blade, streak plate

What test would you do to see whether a mineral has sodium, potassium, or calcium in it?

flame test

Mineralogists look at the _______ and _________ properties of small samples of a _______ taken from the location of _______. Such tests help geologists _______,________, and ______ minerals and better _______ the geologic setting that they come from.

physical; chemical; mineral; study; identify; classify; analyze; understand

You are trying to identify a sample of a mineral. It is brassy yellow with a metallic luster, has conchoidal fracture, a hardness between 6 and 6.5, and a specific gravity of 5.08. What is it?

pyrite

Small amounts of certain isotopes have caused _?_ in these minerals.

radioactivity

What are three additional tests on minerals, though not as often, that geologists use?

radioactivity, luminescence, and refraction

The mineral calcite has the property of _?_.

refraction

Symmetry

the geometry term that describes how one part of a geometric figure is related to its other parts

Why do mineralogists use the magnetism test?

to simply test to see whether a magnet will attract a mineral or its powder

The fracture property may be.....

uneven (rough surface), hackle (fine points), fibrous, or conchoidal (glassy, clamshell-like chips)

Specimen

what mineralogists sometimes call a small piece of a mineral

What mineral represents a tetragonal mineral system?

zircon

What are examples of minerals that react with acids?

Calcite, dolomite, and galena

True or False: Light reflects from the tiny particles of the mineral's powder in the same way that it does from the mineral's crystal structure.

False

The rocky area pictured is called an _?_. - a rocky area that was recently explored

outcrop

What are the five ratings that mineralogists have for mineral cleavage?

perfect, good, fair, poor, and none

What values does the Mohs Hardness Scale range?

1-10

Name the lusters of the following: - Quartz - Gypsum - Diamond - Asbestos

1. glassy/vitreous luster 2. pearly luster 3. adamantine luster 4. silky luster

What are the properties that most mineralogists use to identify most minerals?

Color, streak, luster, crystal shape, cleavage, fracture, hardness, and specific gravity.

Mineralogists

geologist who studies minerals including their formation, composition, structure, and alteration