GIA JUNIOR GEMOLOGIST PROGRAMTM

Table of ContentsAbout GIA..........................................................................................1

Geology and Gems..........................................................................3

What Is a Rock? ..............................................................................4

Rock Cycle—New Rocks from Old ..............................................5

Minerals ............................................................................................7

What Is a Mineral? ..........................................................................8

Mohs Scale of Hardness ............................................................10

Mohs Scale of Hardness Worksheet ........................................11

Gemology ......................................................................................12

What Is a Gem? ............................................................................13

Inclusions ......................................................................................14

Phenomena....................................................................................16

Looking at Phenomena Worksheet ..........................................17

Tools of the Trade ........................................................................18

Gemstone Inclusion Activity ......................................................20

Birthstones and Lore ..................................................................21

Word Search ..................................................................................25

Crossword Puzzle ........................................................................26

Glossary of Terms ........................................................................27Some words in this book are bold. Thesewords have definitions in the glossary atthe end of the book.

Welcome!Dear GIA Junior Gemologists,

The Gemological Institute of America welcomes you!

Today you will get a glimpse into the amazing worldof gemology. You’ll learn what we do at GIA andwhat makes the study of gems so fascinating. You’llget to look inside gemstones using the tools of thetrade and see for yourself what makes each gemunique.

We’re certain your time with us will be exciting, andwe hope it’s just the start of a life-long interest ingems and gemology.

Enjoy your experience and please come back and seeus again.

Sincerely,

Guest Services

GIA World Headquarters andThe Robert Mouawad Campus5345 Armada Drive Carlsbad, CA 92008T 800 421 7250 T 760 603 4000, ext 4116 F 760 603 4199E guestservices@gia.eduwww.gia.edu

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About GIAWe’re a school. We’re a laboratory. Many scientists andteachers work here. We’ve been teaching students gemology(the study of gemstones), developing equipment, and settingstandards in the gem and jewelry industry since 1931.

People come from all over the world to study at GIA. Theywant to work in the gem and jewelry industry. We teach people how to identify and evaluate gems. And we teachthem how to design and make jewelry.

We have the world’s largest gemological library. It’s calledthe Richard T. Liddicoat Gemological Library and InformationCenter. We collect and preserve books about gems andjewelry. We have over 38,000 books. Our oldest one datesback to 1496.

We also collect and preserve mineral specimens, jewelry,gem art, and gemological equipment.

We have beautiful gems on display at our schools aroundthe world.

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Geology and GemsGeology is the science and study of the earth.

The forces shaping the earth’s surface build and wear downhuge mountain chains over millions of years. They crush,melt, and change vast volumes of rock. And every time heatand pressure force rocks to change, gems might form.

Geology helps gem prospectors decide where to look fornew gem sources. They know that certain gem depositsare associated with certain types of rock. This helps themnarrow down the search for gems.

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Someone who studies geology iscalled a

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What Is a Rock?Rocks are a combination of minerals and are the buildingblocks of the earth. They tell a story about the earth and how itwas formed. Some rocks form at or near the earth’s surfaceand others form deep in the earth’s crust or in the middle layerof the earth called the mantle.

Although there are many kinds of rocks, geologists classifythem into three groups based on how they’re formed:

Igneous rocks, such as lava, obsidian, pumice, and granite,start out in a molten or semi-molten state and become solidwhen they cool.

Sedimentary rocks, like sandstone, shale, and limestone, areformed by layers of sediments squeezed and pressed togetherover a long period of time.

Metamorphic rocks, such as slate, schist, and marble, havetheir makeup, texture, or structure changed by great heat,pressure, or both.

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Name a rock that formsby each process:

1. Igneous

2. Sedimentary

3. Metamorphic

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Rock Cycle—New Rocks from OldThe rock cycle is a recycling process that never stops. Itmakes new rocks from old ones. If the rocks are deepunderground, they’re altered or melted by the earth’s innerforces. If they’re at the surface, weathering—exposure towater, wind, and other environmental conditions—breaksthem down. Erosion may move the rocks far from their orig-inal location. The broken-down rocks are buried, altered bypressure, or melted by high temperatures to begin the cycleagain.

sedimentary

metamorphic

igneous

mantle

crust

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A person who studies mineralogy iscalled a

MineralsIf rocks are the building blocks that make up the earth, then minerals are the stuff that rocks are made of.

Mineralogy is the study of minerals and how they’re formed.

R i ch a r d T . L i d d i co a t

What Is a Mineral?First of all, minerals must be solid. They can’t be gases orliquids.

Second, minerals have never been alive—they’re inorganic.Inorganic materials are composed of non-living matter. They’redifferent from organic materials, like coral or ivory, that aremade by or come from living organisms.

Minerals are made by nature, not by human hands. A mineral can’t be made by scientists in a laboratory.

Minerals are made of atoms, which are the basic structuralunits of matter. They’re nature’s building blocks. Mineralsalmost always form as crystals. A crystal is solid matter withatoms arranged in a regular, repeating, three-dimensionalpattern. Mineralogists call this crystal structure.

A final feature all minerals share is a specific chemicalcomposition, which is sort of like a recipe. A mineral’schemical composition is its unique combination of atoms.The recipe has to be perfect to grow a particular mineral.For example, you can’t substitute salt in place of sugar ina cookie and still get a cookie. The same holds true forminerals.

Large mineral crystals grow when there’s just the rightheat, pressure, and time. Minerals can take on very beautifulcrystal forms. A mineral’s crystal form is an exteriorexpression of its internal atomic structure. A crystal’s shapeis determined by the pattern the atoms follow. Crystals arethe raw material for most of the gems in jewelry.

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List five features of a mineral:

1.

2.

3.

4.

5.

atoms

combined atoms—the recipe for this mineral

crystal structure—a regular, repeating arrangement of atoms

crystal

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Mohs Scale ofHardnessSome gems are harder than others. Some scratch easily. It’seasier to scratch a fluorite than a diamond.

In 1822, a German professor and mineralogist namedFriedrich Mohs (MOZE) developed a system for rating therelative hardness of minerals. Because diamond scratchedevery other mineral, he gave it the number 10.

The Mohs scale can be confusing. Without knowing anythingelse about the minerals on the list, you might think that dia-mond is only a little harder than corundum. In fact, destruc-tive scratch tests done with a diamond-tipped, weightedlever show that diamond is 140 times harder than corun-dum and almost 124,000 times harder than talc.

Many everyday items measure about a 7 on the Mohs scale,like a drinking glass for example. Any gem that has a lowerMohs scale rating than topaz might pick up some scratchesfrom even the most careful wear. Even scratchy fabrics likewool can, over time, strip away the lustrous outer layer of apearl.

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softer or harder

#2

softer or harder

#3

softer or harder

In boxes 1-3, circle whether the minerals in your canister are harder or softer than the tester mineral.

Mohs Scale of Hardness Worksheet

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TESTER MINERAL:

GemologyGemology is the study of gems.

A person who identifies and evaluatesgemstones is called a

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What Is a Gem?Almost all gems are minerals, but very few minerals qualifyas gems. To be a gem, a mineral must be beautiful, rare, anddurable. These three things make a gem desirable.

All gems should be beautiful. But because beauty is in theeye of the beholder, people don’t always agree what’sbeautiful and what isn’t. Most people consider that beautyis a combination of qualities that delight the senses orappeal to the mind.

Rarity means there isn’t very much of something; it’s noteasily found. Some gems are rarer than others. A few, likesphene or benitoite, are so rare they’re considered collec-tors’ items. Others, like amethyst or sapphire, are moreavailable.

To qualify as a gem, something must also be durable.Durability is a combination of three factors: hardness,toughness, and stability. Hardness measures how well agemstone resists scratching and abrasion. Toughness is agem’s ability to withstand breaking, chipping, and cracking.Stability measures how well a gemstone resists the effectsof light, heat, and chemicals.

List three features of a gem:

1.

2.

3.

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InclusionsWhat do inclusions tell us? They tell us whether a gemstonegrew in the earth, or in a laboratory. A tiny cluster of mineralcrystals in a ruby is nature’s signature. The gleam of a tinycrystal in a gem is a window into the depths of the earth.Inclusions are silent witnesses to the birth of gems. They tellus how a gem formed, sometimes even where it grew.

Gems have many different kinds of inclusions. They can beother minerals, gases, or liquids. In organic materials likeamber, inclusions can be things like leaves, bugs, or tree bark.

Inclusions serve as fingerprints for gemstones since no twogems have the exact same inclusions. Because of the waygems form, the chances of a truly inclusion-free gem areextremely rare.

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PhenomenaSome gems display special effects when they interact withlight. These stones are called phenomenal gems because theydisplay unusual optical effects.

Phenomenal gems like opal, moonstone, and fire agate gettheir dazzling special effects from the way their structures interact with light. Some can change color in different lightingor reveal special effects when viewed in a certain direction.

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1. Asterism—Crossing bands of light, which create a star inthe dome of the cabochon.

2. Adularescence—A cloudy bluish white light, caused byscattering of light.

3. Aventurescence—A glittery effect caused by light reflecting from small, flat inclusions within a gemstone.

4. Chatoyancy—A band of light in certain gems, caused byreflection of light from many parallel, needle-like inclusions or hollow tubes (cat’s eye, tiger’s eye).

5. Iridescence—A rainbow effect, similar to light reflected onsoap bubbles, created when light is broken up into spec-tral hues by thin layers.

6. Play-of-color—Flashing rainbow colors that sparkle aslight moves around the gem.

Looking at Phenomena WorksheetHere’s a list of the different phenomena you might see in gems. Use a penlight to look at gems 1 through 6. Draw

the effect you see in each box. Write the name of each gem.

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Tools of the TradeGemologists often use binocular microscopes to look at gems.“Binocular” means you look with both eyes, which is more com-fortable than looking through a single eye piece. Like a loupe, amicroscope can magnify an object 10 times its size. But unlike aloupe, it goes up to 64X. That means your object will appear 64times bigger! Microscopes can help you see things that aren’t visible under 10X magnification. Microscopes have two types oflighting: reflected lighting to examine the surface of stones anddarkfield lighting to examine the inside of stones.

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A loupe is a handheld magnifier. It’s capable of makingan object appear 10 times larger than it actually is. 10Xis the standard magnification used throughout the gemand jewelry industry to look at gemstones. Benefits of aloupe are that it’s portable and easy to use once you getthe hang of it.

A darkfield loupe is a handheld magnifier with its ownlight source. Darkfield illumination means that you’relighting the gemstone from the side against a built-inblack, non-reflective background. This helps you to seeinside the gem.

Tweezers are the instrument gemologists use to holdstones. They help prevent the oils from your fingers fromgetting on the gem. They’re also used for sorting largequantities of small stones.

A stone cloth is used to remove debris and oils fromstones. It also keeps your stone in a safe place whileyou’re examining it.

A penlight is a small handheld light source that is the sizeof a pen. It supplies additional lighting and is used tocheck for phenomena in gemstones.

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OverviewExamine gemstones and draw the gemstone inclusions you see.

TaskExamine the gemstone samples in your canister. First, examine the samples with your unaided eye. Then, examine thegemstones with the required tools. Draw what you see inside the stone. Write “none” if you don’t see any inclusions.

Gemstone Inclusion Activity

Gemstone 1 Gemstone 2

Gemstone 3 Gemstone 4

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Birthstonesand Lore

What’s your birthstone?

On the following pages you will find out the hardness

of your birthstone based on the Mohs scale, and which

powers your special stone has.

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April—Diamond

The most common color of diamond is brownto light yellow. Diamonds can be many differentcolors as well as colorless. Hardness 10

Lore: Diamond symbolizes invincibility and gives itswearer superior strength and good fortune.

May—Emerald

Emerald is the green version of beryl. Ancientwritings tell us that emeralds were found inCleopatra’s mines in Egypt. Hardness 71/2—8

Lore: Emerald is believed to heal the bites of ven-omous creatures and help memory. It endows itswearer with the ability to see into the future.

June—Pearl

Pearls are translucent to opaque and virtuallyany body color, but usually white or light yel-low (called cream). Pearls come from oysters

and other mollusks. Pearls can be tiny or large,round or irregular, and everything in between. Hardness 21/2—4

Lore: Pearls are thought to cure ailments of the heartand aid in peace of mind. They pull together one’smental and spiritual forces.

June—Moonstone

Moonstone is colorless to white, occasionallygreen, orange, yellow to brown, or gray tonearly black. Hardness 6—61/2

Lore: Moonstone is believed to bring good fortune,cure epilepsy, encourage serenity, and even helpswimmers avoid accidents in the water.

January—Garnet

Most garnets you see are dark red, but the mostvaluable garnets are brilliant green or orange.Hardness 7—71/2

Lore: Garnets are believed to have curative powers.They cure depression, guard against injury, and protectagainst poisons. They give the wearer loyalty and anunchanging heart.

February—Amethyst

Amethyst is purple quartz. It is one of the most popular stones used in jewelry. Hardness 7

Lore: Amethyst is said to control evil thoughts, quick-en intellect, sharpen sense of sight, and protect wearer fromsorcery.

March—Aquamarine

Aquamarine’s name comes from “aqua,” whichmeans water and “marine,” which means sea. It isthe light blue version of beryl. Hardness 71/2—8

Lore: Aquamarine is thought to cure pain in the throat,stomach, liver, and jaw. It protects against perils at seaand ensures safe voyages.

March—Bloodstone

Bloodstone is semitranslucent to opaque, dark greenwith red to brownish red spots. Hardness 61/2—7

Lore: Bloodstone is believed to help stop blood flowfrom wounds, give courage and wisdom to its wearers andenable them to uncover enemy plots.

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June—Alexandrite

Alexandrite changes color under differentlighting. In daylight or fluorescent light itlooks yellowish, brownish, grayish or bluishgreen; in incandescent light it looks orangy orbrownish red to purple red. Hardness 81/2

Lore: Alexandrite is thought to help cure spleen andpancreas disorders. Alexandrite pulls sacred firestogether and stabilizes them.

July—Ruby

Ruby is the red variety of corundum. Largetransparent rubies are even rarer than dia-monds. Hardness 9

Lore: Rubies are said to give courage and protectagainst pain and poison. Rubies are believed topreserve fruit on trees. They remove evil thoughts,preserve mental health, and make the wearerinvincible to steel, swords, spears, and daggers.(Don’t try this at home!)

August—Peridot

Peridot is found in volcanic flows and even inmeteorites from space called “pallasite.” It isa yellowish green stone. Hardness 61/2—7

Lore: Peridot is thought to aid in digestion and easeemotions. It purifies and balances physical being.

August—Sardonyx

Sardonyx is semitransparent to opaque withwhite or black bands alternating with reddishbrown bands. Hardness 61/2—7

Lore: Sardonyx is believed to protect its wearer frombites of venomous snakes and gives one the power of eloquence. It attracts quality friends and curesinsomnia.

September—Sapphire

Sapphires come in nearly every color of therainbow except for red; red sapphires areknown as rubies. Hardness 9

Lore: Sapphires are thought to offer special healingpowers for profuse sweating, ulcers, eye trouble, andhemophilia.

October—Opal

Opals come in virtually any body color, displaying iridescent flashes called “play-of-color.” Opals are sensitive stones, and might

crack if they get too hot or too dry. Hardness 5—61/2

Lore: Opals are thought to provide the power ofprophecy and preserve golden color in blond women’shair. They empower its wearer with invisibility by dimming the eyes of the beholder.

October—Tourmaline

Tourmaline is transparent to opaque andcomes in virtually all colors. Hardness 7—71/2

Lore: Tourmaline is said to protect against fallson a journey and helps its wearer to be more objec-tive. It also fosters inspiration and diminishes fears.

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November—Topaz

Natural blue topaz is very uncommon innature. Most blue topaz has been treated withradiation and then heated, which turns it blue.Hardness 8

Lore: Topaz is believed to endow its wearers withlong life, beauty, intelligence, and sweet dreams.

November—Citrine

Citrine is transparent, yellow to orange tobrownish orange quartz. Hardness 7

Lore: Citrine is thought to dissipate negative energy,purify body toxins, and cure liver and kidney disorders.

December—Zircon

Zircon is transparent and can be colorless,blue, yellow, green, brown, orange, red, andoccasionally purple. Hardness 6—71/2

Lore: Zircon is believed to dispel sadness, insomnia, and increase the wearer’s riches, honor,and wisdom.

December—Turquoise

Turquoise is semitranslucent to opaque, lightto medium blue, or greenish blue to green.It’s most often mottled and might show darksplotches or veins of matrix. Hardness 5—6

Lore: Turquoise is said to protect its wearer and thewearer’s horse from injury. It counteracts spells andaids one’s intuition.

December—Tanzanite

Tanzanite is transparent and can be blue toviolet to bluish purple. Hardness 6—7

Lore: Tanzanite is believed to have potent healingabilities.

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Word SearchASTERISM

EROSION

LOUPE

PENLIGHT

SPECIES

CHATOYANCY

GEMSTONE

METAMORPHIC

ROCK

TWEEZERS

CRYSTAL

IGNEOUS

MINERAL

SEDIMENTARY

VOLCANIC

Answers on page 29

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Crossword PuzzleAcross

2. One of the December birthstones

3. A birthstone thought to provide powers of prophecy

5. Unit of measurement for gem weight

8. A tabletop magnifier

10. A gem’s ability to withstand wear, heat, and chemicals

Down

1. A person who studies mineralogy

4. This organic gem is the birthstone for June

6. The basic unit of all matter

7. Small, portable magnifying lens

9. City where the GIA headquarters is located

Answers on page 29

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Glossary of TermsAdularescence—The cloudy bluish white light in a moon-

stone, caused by scattering of light.

Asterism—Crossing bands of light, which create a star in thedome of a cabochon.

Atom—The basic structural unit of all matter.

Aventurescence—A glittery effect caused by light reflectingfrom small, flat inclusions within a gemstone.

Binocular microscope—A tabletop magnifier with two eye-pieces.

Carat—Unit of measure for gemstones, equal to 0.2 gram or200 milligrams, abbreviated “ct.”

Chatoyancy—A band of light in certain gems, caused byreflection of light from many parallel, needle-like inclusions or hollow tubes.

Chemical composition—Kinds and relative quantities ofatoms that make up a material.

Crystal structure—Regular, repeating internal arrange-ment of atoms in a material.

Darkfield illumination—Lighting of a gemstone from the sideagainst a black, non-reflective background.

Durability—A combination of three factors: hardness,toughness, and stability.

Erosion—The transport of rock materials by natural forces.

Gem—A mineral that is beautiful, rare, and durable.

Gem species—A broad gem category based on chemicalcomposition and crystal structure.

Gem variety—A subcategory of species, based on color,transparency, or phenomenon.

Gemologist—A person who studies gemology.

Gemology—The study of gems.

Geologist—A person who studies geology.

Geology—The study of the earth.

Group—A family of gems made up of several closely relatedmineral species.

Hardness—How well a gem stone resists scratches andabrasion.

Igneous—Rock formed by the crystallization of moltenmagma.

Inclusion—A characteristic enclosed within a gemstone orreaching its surface from the interior.

Inorganic—Composed of, or arising from, non-living matter.

Iridescence—A rainbow effect created when light is broken up into spectral hues by thin layers.

Karat—A unit of measure for the fineness of gold,abbreviated “k” or “kt.”

Lore—Facts, traditions, or beliefs about gemstones.

Loupe—A small, portable magnifying lens used for examining gemstones.

continued on next page

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Metamorphic—Rock altered by heat and/or pressure, or by heated fluids from magma.

Mineral—A natural, inorganic substance with a specificchemical composition and a repeating crystal structure.

Mineralogist—A person who studies mineralogy.

Mineralogy—The study of minerals.

Mohs scale—Used to rank the relative hardness of mineralson a scale of one to ten.

Natural gems—Gems produced by natural processes,without human help.

Organic—Produced by, or derived from, a living oronce living organism.

Penlight—A portable, handheld light source the size of a pen.

Play-of-color—The flashing rainbow colors in opal.

Rock cycle—A constant formation and recycling processthat creates new rock from old.

Rock—A natural material made up of two or more minerals.

Sedimentary—Rock produced from the weathered anderoded remains of existing rocks.

Stability—measures how well a gemstone resists the effectsof light, heat, and chemicals.

Stone cloth—Piece of fabric used for cleaning dirt and oilfrom gems and holding them in place.

Synthetic—Manufactured in a labaratory.

PHOTO CREDITS

Joel Beeson, 8

BHP, 2

Valerie Power, 1 (bottom), 16 (bottom left)

Terri Weimer, 19 (top right)

Eric Welch, cover photo (right), Table of Contents,2, 3 (left and right), 6, (right), 18, 19 (left)

Robert Weldon, 1 (top left and right), 12, 16 (bottomright), 19 (bottom right)

ILLUSTRATION CREDITS

Judy Colbert, 21

Peter Johnston, cover (left), 5, 9, 10

Toughness—A gem’s ability to withstand breaking, chipping, and cracking.

Tweezers—An instrument for holding gemstones.

Weathering—Exposure to water, wind, and other environmental conditions.

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Answers to Word Search Answers to Crossword Puzzle

©20 1 1 T h e G em o lo gi ca l I n st i tu te o f A m er i caA ll r igh t s r eser v ed : P r o tected u n d er th e B er n e C on v en t i o n .P r in ted in th e U n i ted S t a tes.

GIA’s mission is to ensure the public trust in gems and jewelry by upholding thehighest standards of integrity, academics, science, and professionalism througheducation, research, laboratory services, and instrument development.

GIA was established in 1931 by Robert M. Shipley. Mr. Shipley wanted to create aninstitute that would serve the gem and jewelry industry by providing education tojewelers.

The GIA Junior Gemologist ProgramTM is just one part of Robert Shipley’s legacy. Tolearn more, we invite you to visit our website www.gia.edu

GIA World Headquarters andThe Robert Mouawad Campus5345 Armada Drive Carlsbad, CA 92008T 800 421 7250 T 760 603 4000, ext 4116 F 760 603 4199E guestservices@gia.eduwww.gia.edu