Encyclopedia

Mineral Guide

Billions of years of geological wonder — explored, explained, and celebrated.

Showing 138 of 138 specimens

Gemstone

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Agate

Also Known As: Chalcedony Agate · Banded Agate

Common Colors:Banded (all colors)BlueRed+4

Brazil, Uruguay +5 more

Gemstone

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Almandine

Also Known As: Almandite · Common Garnet

Common Colors:Deep RedRed-BrownViolet-Red+1

India, Sri Lanka +5 more

Mineral

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Amazonite

Also Known As: Amazon Stone · Amazon Jade

Common Colors:TealBlue-GreenMint Green+1

Russia (Ural Mountains), USA (Colorado) +4 more

Organic

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Amber

Also Known As: Baltic Amber · Succinite

Common Colors:Golden YellowOrangeCognac Brown+2

Baltic Sea region (Poland, Lithuania, Russia), Dominican Republic +3 more

Crystal

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Amethyst

Also Known As: Bishop's Stone · Violet Quartz

Common Colors:PurpleVioletLavender+1

Uruguay, Brazil +4 more

Gemstone

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Ametrine

Also Known As: Trystine · Bolivianite

Common Colors:Purple and YellowViolet and GoldBicolor Quartz

Bolivia (Anahi Mine — primary source), Brazil +1 more

Fossil

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Ammonite

Also Known As: Ammolite (iridescent gem variety) · Draconite (medieval name)

Common Colors:BrownGrayIridescent (ammolite variety)+1

Morocco, Canada (Alberta — ammolite) +4 more

Mineral

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Andalusite

Also Known As: Chiastolite (cross-bearing variety) · Viridine (green variety)

Common Colors:BrownRed-BrownGreen+3

Spain (Andalusia), Brazil +4 more

Gemstone

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Andradite

Also Known As: Demantoid (green gem variety) · Melanite (black variety)

Common Colors:Yellow-Green (demantoid)Black (melanite)Yellow (topazolite)+2

Russia (Ural Mountains), Italy +5 more

Mineral

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Angelite

Also Known As: Blue Celestite · Celestine

Common Colors:Pale BlueBlue-GrayWhite+1

Peru, Germany +4 more

Mineral

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Apache Tears

Also Known As: Marekanite · Pele's Tears (teardrop form)

Common Colors:BlackDark BrownTranslucent Gray (when held to light)

USA (Arizona, Nevada, New Mexico), Mexico

Mineral

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Apatite

Also Known As: Asparagus Stone (yellow-green variety) · Moroxite (blue-green variety)

Common Colors:BlueGreenYellow+4

Mexico, Brazil +5 more

Mineral

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Apophyllite

Also Known As: Fish-Eye Stone · Cleavelandite (variety)

Common Colors:ClearWhiteGreen+2

India (Pune), Brazil +4 more

Gemstone

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Aquamarine

Also Known As: Sea Beryl · Blue Beryl

Common Colors:Sky BlueSea BlueBlue-Green+1

Brazil (Minas Gerais), Pakistan +4 more

Mineral

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Aragonite

Also Known As: Flos Ferri (cave variety) · Satin Spar (fibrous)

Common Colors:WhiteColorlessOrange+3

Spain (Molina de Aragón), Morocco +4 more

Mineral

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Augite

Also Known As: Common Pyroxene · Black Pyroxene

Common Colors:BlackDark BrownDark Green+1

Worldwide in volcanic and plutonic rocks, Italy (Vesuvius) +3 more

Gemstone

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Aventurine

Also Known As: Indian Jade (trade name) · Green Quartz

Common Colors:GreenBlueRed-Brown+2

India, Brazil +4 more

Mineral

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Axinite

Also Known As: Tinkhamite (manganese-rich variety) · Ferroaxinite (iron-rich)

Common Colors:BrownViolet-BrownClove Brown+3

France (Bourg d'Oisans), Mexico +5 more

Mineral

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Azurite

Also Known As: Blue Malachite · Chessylite

Common Colors:Deep Azure BlueVivid Cobalt BlueBlue-Green (when mixed with malachite)

Morocco, USA (Arizona) +4 more

Mineral

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Barite

Also Known As: Heavy Spar · Barytine

Common Colors:WhiteColorlessBlue+3

USA, China +5 more

Mineral

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Beryl

Also Known As: Emerald (green) · Aquamarine (blue)

Common Colors:Green (emerald)Blue (aquamarine)Pink (morganite)+3

Brazil, Colombia +5 more

Mineral

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Bismuth

Also Known As: Native Bismuth · Bismite (oxide form)

Common Colors:Silver-White (native)Iridescent Rainbow (lab-grown crystals)Pink+2

Bolivia, Peru +5 more

Mineral

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Biotite

Also Known As: Black Mica · Iron Mica

Common Colors:BlackDark BrownBronze+1

Worldwide — extremely common in granite, gneiss, and schist

Gemstone

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Black Onyx

Also Known As: Onyx · Black Chalcedony

Common Colors:Jet BlackBlack with White BandsDark Brown-Black

Brazil, India +4 more

Crystal

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Black Tourmaline

Also Known As: Schorl · Aphrizite

Common Colors:Jet BlackDark Brown-Black

Brazil, Pakistan +4 more

Gemstone

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Bloodstone

Also Known As: Heliotrope · Plasma (dark green variety)

Common Colors:Dark GreenDark Green with Red SpotsGreen-Gray with Red Flecks

India, Brazil +4 more

Gemstone

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Blue Lace Agate

Also Known As: Blue Chalcedony · Lace Agate

Common Colors:Pale BlueSky BlueBlue-White Banded+1

Namibia (primary source), South Africa +3 more

Mineral

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Bornite

Also Known As: Peacock Ore · Peacock Copper

Common Colors:Iridescent PurpleBlueGold+2

USA (Montana, Arizona), Peru +4 more

Mineral

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Calcite

Also Known As: Iceland Spar (optical) · Dogtooth Spar

Common Colors:WhiteOrangeYellow+4

Mexico, USA +4 more

Gemstone

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Carnelian

Also Known As: Cornelian · Sardius (biblical name)

Common Colors:OrangeRed-OrangeDeep Red+1

Brazil, India +4 more

Mineral

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Cassiterite

Also Known As: Tin Stone · Stream Tin

Common Colors:BlackBrownYellow-Brown+2

China, Indonesia +5 more

Mineral

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Celestite

Also Known As: Strontianite (related mineral) · Blue Celestite

Common Colors:Pale BlueSky BlueWhite+2

Madagascar, USA (Ohio) +4 more

Mineral

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Chabazite

Also Known As: Phacolite (variety) · Acadialite (variety)

Common Colors:WhiteColorlessYellow+3

India (Deccan Traps), Germany +5 more

Gemstone

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Chalcedony

Also Known As: White Chalcedony · Siliceous Sinter

Common Colors:BlueWhiteGray+2

Turkey, Brazil +4 more

Mineral

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Chalcopyrite

Also Known As: Copper Pyrite · Yellow Copper Ore

Common Colors:Brassy YellowGoldIridescent Blue-Purple-Gold (tarnished)

Chile, USA +5 more

Mineral

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Charoite

Also Known As: Charoite Jade (trade name) · Siberian Purple Stone

Common Colors:VioletLavenderPurple+1

Russia (Murun massif, Siberia — only known source)

Gemstone

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Chrysoberyl

Also Known As: Cat's Eye Chrysoberyl · Cymophane

Common Colors:YellowYellow-GreenGreen+2

Brazil, Sri Lanka +4 more

Mineral

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Chrysocolla

Also Known As: Gem Silica · Blue Chrysocolla

Common Colors:Turquoise BlueBlue-GreenCyan+1

USA (Arizona), Peru +4 more

Gemstone

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Chrysoprase

Also Known As: Australian Jade (trade name) · Green Chalcedony

Common Colors:Apple GreenBright GreenMint Green+1

Australia (Queensland), Poland +4 more

Mineral

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Chlorite

Also Known As: Chlorite Schist (rock form) · Clinochlore (common variety)

Common Colors:GreenDark GreenYellow-Green+3

USA, Brazil +5 more

Mineral

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Cinnabar

Also Known As: Vermilion (pigment form) · Dragon's Blood (Chinese name)

Common Colors:Scarlet RedVermilionBrick Red+1

China (Hunan Province), Spain (Almadén) +3 more

Crystal

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Citrine

Also Known As: Merchant's Stone · Success Stone

Common Colors:YellowGolden OrangeAmber+1

Brazil, Bolivia +4 more

Crystal

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Clear Quartz

Also Known As: Rock Crystal · Master Healer

Common Colors:ColorlessWhiteTransparent

Brazil, USA +4 more

Mineral

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Copper

Also Known As: Native Copper · Copper Nugget

Common Colors:Copper-RedOrange-RedGreen (patinated)+1

USA (Michigan), Chile +4 more

Gemstone

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Corundum

Also Known As: Ruby (red variety) · Sapphire (blue/other gem colors)

Common Colors:Deep Red (ruby)Blue (sapphire)Pigeon Blood Red+5

Myanmar (Mogok), Thailand +6 more

Mineral

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Danburite

Also Known As: Bohemian Diamond (historical) · Danburite Crystal

Common Colors:ColorlessWhitePale Yellow+1

Mexico (Charcas), Japan +4 more

Gemstone

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Diamond

Also Known As: Carbonado (black diamond) · Brilliant (cut form)

Common Colors:ColorlessYellowBrown+3

Russia, Botswana +4 more

Mineral

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Desert Rose

Also Known As: Sand Rose · Gypsum Rose

Common Colors:TanSandy BrownCream+2

Morocco, Algeria +5 more

Mineral

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Diopside

Also Known As: Chrome Diopside (green variety) · Black Star Diopside

Common Colors:Dark GreenBlackWhite+3

Russia (Siberia — chrome diopside), India (black star) +5 more

Mineral

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Dioptase

Also Known As: Emerald Copper (trade name) · Copper Emerald

Common Colors:Vivid Emerald GreenDeep Teal GreenBlue-Green

Namibia (Tsumeb), Democratic Republic of Congo +4 more

Mineral

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Dolomite

Also Known As: Pearl Spar · Bitter Spar

Common Colors:WhitePinkPeach+3

Italy (Dolomite Mountains), USA +4 more

Mineral

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Dumortierite

Also Known As: Blue Dumortierite · Dumortierite Quartz

Common Colors:Deep BlueViolet-BlueBlue-Gray+1

USA (Nevada, California), France +4 more

Gemstone

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Emerald

Also Known As: Green Beryl · Smaragd (German/historical)

Common Colors:Vivid GreenDeep Forest GreenYellow-Green+1

Colombia (Muzo, Chivor), Zambia +4 more

Mineral

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Enstatite

Also Known As: Bronzite (iron-rich variety) · Hypersthene (iron-rich variety)

Common Colors:GrayGreenish-GrayBrown+3

South Africa, Myanmar +5 more

Mineral

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Epidote

Also Known As: Pistacite (iron-rich variety) · Tawmawite (chromium variety)

Common Colors:Pistachio GreenYellow-GreenDark Green+1

Austria (Knappenwand), Pakistan +4 more

Mineral

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Feldspar

Also Known As: Orthoclase (common variety) · Microcline (variety)

Common Colors:PinkWhiteGray+3

Worldwide — found on every continent and in most rock types

Gemstone

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Fire Opal

Also Known As: Mexican Fire Opal · Sun Opal

Common Colors:OrangeRed-OrangeYellow-Orange+1

Mexico (Querétaro — primary source), USA +4 more

Mineral

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Fluorite

Also Known As: Fluorspar · Genius Stone

Common Colors:PurpleGreenBlue+4

China, Mexico +4 more

Mineral

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Fuchsite

Also Known As: Green Mica · Chrome Mica

Common Colors:Emerald GreenBright GreenSparkly Green (with mica shimmer)

Brazil, India +4 more

Mineral

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Galena

Also Known As: Lead Glance · Blue Lead

Common Colors:Lead GraySilver-GrayMetallic Black

USA (Missouri, Idaho), Germany +4 more

Gemstone

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Garnet

Also Known As: Almandine (red variety) · Pyrope (deep red)

Common Colors:Deep RedOrange (Spessartine)Green (Tsavorite/Demantoid)+2

India, Brazil +5 more

Mineral

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Gold

Also Known As: Native Gold · Electrum (gold-silver alloy)

Common Colors:Golden YellowPale YellowOrange-Yellow

South Africa (Witwatersrand), Australia +4 more

Gemstone

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Grossular

Also Known As: Tsavorite (green gem variety) · Hessonite (orange variety)

Common Colors:Green (tsavorite)Orange (hessonite)Yellow+4

Kenya (tsavorite), Tanzania +5 more

Mineral

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Gypsum

Also Known As: Alabaster (fine-grained form) · Selenite (crystalline form)

Common Colors:WhiteColorlessPink+3

USA (New Mexico — White Sands), Mexico (Cave of Crystals) +4 more

Mineral

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Halite

Also Known As: Rock Salt · Table Salt

Common Colors:ColorlessWhitePink+3

USA (Kansas, Michigan), Germany +4 more

Mineral

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Hematite

Also Known As: Bloodstone (historical) · Iron Ore

Common Colors:Silver-GrayBlackRed-Brown (earthy)

Brazil, Australia +4 more

Mineral

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Hemimorphite

Also Known As: Calamine (historical) · Electric Calamine

Common Colors:Sky BlueBlue-GreenWhite+2

China, Mexico +4 more

Mineral

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Hornblende

Also Known As: Common Hornblende · Black Hornblende

Common Colors:BlackDark GreenDark Brown

Worldwide — extremely common in igneous and metamorphic rocks

Mineral

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Howlite

Also Known As: White Buffalo Stone (trade name) · White Turquoise (misnomer)

Common Colors:WhiteChalk WhiteWhite with Gray-Black Veins

USA (California, Nova Scotia), Canada +3 more

Gemstone

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Iolite

Also Known As: Water Sapphire · Viking's Compass Stone

Common Colors:Blue-VioletIndigoGray-Blue+1

India, Sri Lanka +4 more

Gemstone

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Jade

Also Known As: Nephrite (common variety) · Jadeite (rare variety)

Common Colors:GreenWhiteLavender+3

China, Myanmar (Burma) +4 more

Gemstone

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Jasper

Also Known As: Red Jasper (variety) · Picture Jasper (variety)

Common Colors:RedBrownYellow+3

USA, Brazil +5 more

Mineral

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Kaolinite

Also Known As: Kaolin · China Clay

Common Colors:WhiteCreamPale Yellow+2

China (Jingdezhen — historic source), UK (Cornwall) +4 more

Gemstone

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Kunzite

Also Known As: Pink Spodumene · Lithia Amethyst (historical)

Common Colors:Pale PinkLilacViolet-Pink+1

Afghanistan, Brazil +3 more

Mineral

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Kyanite

Also Known As: Disthene · Rhaeticite

Common Colors:BlueBlue-GrayGreen+2

Brazil, USA (North Carolina) +4 more

Gemstone

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Labradorite

Also Known As: Spectrolite (Finnish variety) · Black Moonstone (trade name)

Common Colors:GrayDark BlueIridescent Blue+3

Canada (Labrador), Finland +4 more

Gemstone

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Lapis Lazuli

Also Known As: Lazurite · Ultramarine Stone

Common Colors:Deep BlueRoyal BlueBlue with Gold Pyrite Flecks+1

Afghanistan (Badakhshan), Chile +4 more

Gemstone

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Larimar

Also Known As: Atlantis Stone · Dolphin Stone

Common Colors:Sky BlueTurquoise BlueBlue-White+1

Dominican Republic (Barahona Province — only known source)

Mineral

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Lepidolite

Also Known As: Lilalite · Lithia Mica

Common Colors:LilacPurplePink+2

Brazil, USA (California) +4 more

Mineral

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Magnetite

Also Known As: Lodestone (magnetic variety) · Magnetic Iron Ore

Common Colors:BlackIron BlackGray-Black

Sweden, USA +5 more

Mineral

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Malachite

Also Known As: Green Copper Ore · Mountain Green

Common Colors:Bright GreenDark Forest GreenBanded Green & Black

Democratic Republic of Congo, Zambia +3 more

Mineral

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Marcasite

Also Known As: White Iron Pyrite · Cockscomb Pyrite (cockscomb habit)

Common Colors:Pale Brass-YellowPale GoldGreenish-Yellow+1

USA, Germany +5 more

Gemstone

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Moldavite

Also Known As: Bouteille Stone · Vltavín (Czech)

Common Colors:Forest GreenOlive GreenBottle Green+1

Czech Republic (Bohemia, Moravia), Germany +1 more

Mineral

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Molybdenite

Also Known As: Molybdenum Glance · Molybdena (historical name)

Common Colors:Lead GraySilver-GrayMetallic Blue-Gray

USA (Colorado, Utah), China +5 more

Gemstone

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Moonstone

Also Known As: Adularia · Hecatolite

Common Colors:WhiteCreamPeach+2

Sri Lanka, India +4 more

Gemstone

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Morganite

Also Known As: Pink Beryl · Rose Beryl

Common Colors:Peach-PinkRoseSalmon+1

Brazil, Madagascar +3 more

Mineral

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Muscovite

Also Known As: White Mica · Common Mica

Common Colors:SilverGoldPale Green+2

India, Brazil +4 more

Mineral

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Natrolite

Also Known As: Needle Zeolite · Soda Zeolite

Common Colors:ColorlessWhitePale Yellow+2

India (Deccan Traps), Germany +5 more

Mineral

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Nuummite

Also Known As: Sorcerer's Stone · Magician's Stone

Common Colors:BlackDark GrayIridescent Gold+1

Greenland (Nuuk region — primary source), Canada +1 more

Mineral

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Obsidian

Also Known As: Volcanic Glass · Xaga (Aztec)

Common Colors:Jet BlackMahogany (brown/black)Rainbow (iridescent)+1

USA (Oregon, Idaho), Mexico +4 more

Mineral

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Olivine

Also Known As: Chrysolite (historical) · Evening Emerald (historical)

Common Colors:Olive GreenYellow-GreenBrown-Green+1

Worldwide in basaltic rocks, Hawaii (green sand beaches) +3 more

Mineral

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Orthoclase

Also Known As: Adularia (low-temperature variety) · Sanidine (high-temperature variety)

Common Colors:WhiteCreamPale Yellow+3

USA, Germany +5 more

Gemstone

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Opal

Also Known As: Precious Opal · White Opal

Common Colors:WhiteBlackCrystal (clear)+1

Australia (Lightning Ridge, Coober Pedy), Ethiopia +3 more

Mineral

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Pectolite

Also Known As: Larimar (blue Dominican variety) · Atlantis Stone (trade name)

Common Colors:WhiteGrayColorless+2

Dominican Republic (Larimar), USA +4 more

Gemstone

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Peridot

Also Known As: Chrysolite (historical) · Evening Emerald (historical)

Common Colors:Lime GreenOlive GreenYellow-Green+1

Pakistan (Kohistan), Egypt (Zabargad Island) +4 more

Gemstone

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Phenacite

Also Known As: Phenakite · White Phenacite

Common Colors:ColorlessWhitePale Yellow+2

Russia (Ural Mountains), Brazil +4 more

Mineral

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Pietersite

Also Known As: Tempest Stone · Eagle Eye (variety)

Common Colors:BlueGoldRed-Brown+2

Namibia (primary source), China

Mineral

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Plagioclase

Also Known As: Albite (sodium variety) · Anorthite (calcium variety)

Common Colors:WhiteGrayPale Green+2

Worldwide — found in most igneous and metamorphic rocks

Mineral

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Prehnite

Also Known As: Grape Jade (trade name) · Cape May Diamond (misnomer)

Common Colors:Pale GreenYellow-GreenMint+2

Australia, South Africa +4 more

Mineral

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Pyrite

Also Known As: Fool's Gold · Iron Pyrite

Common Colors:Brass YellowGoldPale Bronze

Spain (Navajún), Peru +4 more

Mineral

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Pyromorphite

Also Known As: Green Lead Ore · Mimetesite (arsenic variety)

Common Colors:Bright GreenYellow-GreenBrown+3

China, Germany +5 more

Gemstone

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Pyrope

Also Known As: Bohemian Garnet · Cape Ruby (historical misnomer)

Common Colors:Deep RedBlood RedDark Red+2

Czech Republic (Bohemia), South Africa +5 more

Mineral

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Realgar

Also Known As: Ruby Sulfur · Ruby of Arsenic

Common Colors:Bright RedOrange-RedYellow-Orange+1

China, Romania +5 more

Mineral

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Rhodochrosite

Also Known As: Inca Rose · Rosa del Inca

Common Colors:Rose PinkRaspberry RedPale Pink+1

Argentina (Capillitas Mine), USA (Colorado) +4 more

Mineral

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Rhodonite

Also Known As: Manganese Spar · Fowlerite (zinc-bearing variety)

Common Colors:PinkRose RedPink with Black Manganese Veins

Russia (Ural Mountains), Australia +4 more

Crystal

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Rose Quartz

Also Known As: Pink Quartz · Love Stone

Common Colors:Pale PinkRoseSoft Peach

Brazil, Madagascar +3 more

Mineral

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Ruby in Zoisite

Also Known As: Anyolite · Ruby Zoisite

Common Colors:Green (zoisite)Red (ruby)Black (hornblende)+1

Tanzania (Longido — primary source), India +2 more

Mineral

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Rutile

Also Known As: Sagenite (acicular inclusions in quartz) · Venus Hair Stone

Common Colors:Golden YellowRed-BrownBlack+1

Brazil, Australia +4 more

Gemstone

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Sapphire

Also Known As: Corundum (species) · Ceylon Sapphire

Common Colors:Blue (classic)PinkYellow+3

Kashmir (India), Myanmar +4 more

Gemstone

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Sardonyx

Also Known As: Banded Onyx Agate · Arabian Sardonyx

Common Colors:Red-BrownOrange-RedWhite+2

India, Brazil +4 more

Mineral

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Scolecite

Also Known As: Mesolite (related zeolite) · White Scolecite

Common Colors:WhiteColorlessPale Pink+1

India (Pune), Iceland +4 more

Crystal

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Selenite

Also Known As: Satin Spar · Desert Rose

Common Colors:WhiteTranslucentPeach+1

Mexico (Naica), Morocco +3 more

Mineral

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Shungite

Also Known As: Elite Shungite · Noble Shungite

Common Colors:Jet BlackMatte BlackMetallic Black (elite shungite)

Russia (Karelia — primary source), Austria +2 more

Mineral

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Sillimanite

Also Known As: Fibrolite (fibrous variety) · Bucholzite (historical)

Common Colors:WhiteGrayBrown+2

USA (Delaware — state mineral), India +4 more

Mineral

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Silver

Also Known As: Native Silver · Argentum (Latin)

Common Colors:Silver-WhiteGray (tarnished)Black (heavily tarnished)

Mexico, Peru +4 more

Mineral

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Smithsonite

Also Known As: Zinc Spar · Dry Bone Ore

Common Colors:BlueGreenPink+3

Namibia (Tsumeb), USA (New Mexico) +4 more

Crystal

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Smoky Quartz

Also Known As: Cairngorm · Morion (black variety)

Common Colors:BrownGray-BrownDark Charcoal+1

Brazil, Scotland +4 more

Mineral

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Sodalite

Also Known As: Princess Blue (trade name) · Alomite

Common Colors:Royal BlueBlue with White VeinsGray-Blue

Canada (Ontario), Brazil +4 more

Gemstone

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Spessartine

Also Known As: Mandarin Garnet (orange variety) · Fanta Stone (trade name)

Common Colors:OrangeRed-OrangeYellow-Orange+1

Namibia (Mandarin garnet), Nigeria +4 more

Mineral

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Sphalerite

Also Known As: Zinc Blende · Black Jack (dark variety)

Common Colors:YellowOrangeRed+4

USA (Missouri, Kansas), Mexico +4 more

Gemstone

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Spinel

Also Known As: Balas Ruby (historical misnomer) · Pleonaste (iron-rich variety)

Common Colors:RedPinkBlue+4

Myanmar (Mogok), Sri Lanka +4 more

Mineral

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Staurolite

Also Known As: Fairy Cross (cross-shaped twin) · Cross Stone

Common Colors:BrownRed-BrownDark Brown+1

USA (Virginia, Georgia), France +4 more

Mineral

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Stilbite

Also Known As: Desmine (historical) · Peach Stilbite

Common Colors:PeachPinkWhite+3

India (Pune), Iceland +4 more

Mineral

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Sugilite

Also Known As: Royal Lavulite · Royal Azel

Common Colors:PurpleVioletMagenta+2

South Africa (Wessels Mine — primary source), Japan +2 more

Mineral

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Sulfur

Also Known As: Native Sulfur · Brimstone

Common Colors:Bright YellowYellow-OrangeGreenish-Yellow

Italy (Sicily), USA (Louisiana, Texas) +4 more

Gemstone

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Sunstone

Also Known As: Oregon Sunstone · Heliolite

Common Colors:OrangeRed-OrangeGold+2

USA (Oregon), Norway +4 more

Mineral

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Talc

Also Known As: Soapstone (massive form) · Steatite (dense variety)

Common Colors:WhiteGrayGreen+2

USA, China +4 more

Gemstone

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Tanzanite

Also Known As: Blue Zoisite · Violet Zoisite

Common Colors:Blue-VioletDeep IndigoPurple-Blue+1

Tanzania (Merelani Hills — only known source)

Mineral

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Tektite

Also Known As: Libyan Desert Glass · Moldavite (related)

Common Colors:BlackDark BrownOlive Green (Libyan desert glass)+1

Southeast Asia (Indochinites), Czech Republic (Moldavites) +2 more

Gemstone

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Topaz

Also Known As: Imperial Topaz · Blue Topaz

Common Colors:BlueYellowOrange (Imperial)+3

Brazil (Minas Gerais), Pakistan +4 more

Gemstone

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Turquoise

Also Known As: Persian Turquoise · Turkish Stone

Common Colors:Sky BlueRobin's Egg BlueBlue-Green+1

Iran (Nishapur), USA (Arizona, Nevada, New Mexico) +4 more

Mineral

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Unakite

Also Known As: Epidote Granite · Unakite Jasper (misnomer)

Common Colors:Salmon PinkOlive GreenPink and Green Mottled

USA (Unaka Mountains, Blue Ridge), South Africa +3 more

Mineral

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Vanadinite

Also Known As: Red Lead Ore · Vanadate Lead

Common Colors:Bright RedOrange-RedYellow-Orange+1

Morocco (Mibladen, Touissit), USA (Arizona) +3 more

Mineral

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Variscite

Also Known As: Utahlite · Peganite (related mineral)

Common Colors:Apple GreenPale GreenBlue-Green+1

USA (Utah, Nevada), Germany (Vogtland) +3 more

Gemstone

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Watermelon Tourmaline

Also Known As: Elbaite Tourmaline · Bicolor Tourmaline

Common Colors:Pink CoreWhite RindGreen Outer Shell

Brazil, USA (Maine, California) +3 more

Mineral

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Wavellite

Also Known As: Hyalite (colorless variety) · Wavellite Wheel

Common Colors:GreenYellow-GreenWhite+2

USA (Arkansas — primary source), UK (Devon) +3 more

Mineral

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Wulfenite

Also Known As: Yellow Lead Ore · Molybdate Lead

Common Colors:OrangeYellowRed+2

USA (Arizona — Red Cloud Mine), Mexico (Los Lamentos) +3 more

Gemstone

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Zircon

Also Known As: Hyacinth (red variety) · Jargon (pale variety)

Common Colors:BlueGolden YellowRed+3

Australia, Sri Lanka +4 more

Geology 101

The Three Rock Types

Every specimen in our collection was shaped by one of three fundamental geological processes.

Born of Fire

Igneous

Formed from cooled magma or lava. Intrusive igneous rocks (like granite) cool slowly underground, forming large crystals. Extrusive rocks (like obsidian) cool rapidly at the surface, forming fine-grained or glassy textures.

Examples

ObsidianGraniteBasaltPumiceRhyolite

Layers of Time

Sedimentary

Formed from compressed layers of sediment, organic material, or chemical precipitates over millions of years. Most fossils are found in sedimentary rock. Limestone, sandstone, and shale are common examples.

Examples

LimestoneSandstoneShaleFlintChalk

Transformed by Pressure

Metamorphic

Formed when existing rocks are transformed by extreme heat, pressure, or chemically active fluids — without melting. The process recrystallizes minerals into new forms, often creating beautiful banding and foliation.

Examples

MarbleSlateQuartziteSchistGneiss

Reference

The Mohs Hardness Scale

Developed by Friedrich Mohs in 1812, this scale rates a mineral's resistance to scratching from 1 (softest) to 10 (hardest).

Talc

Can be scratched by a fingernail

Gypsum / Selenite

Scratched by a fingernail

Calcite

Scratched by a copper coin

Fluorite

Scratched by a steel knife

Apatite

Scratched by a steel knife with effort

Orthoclase / Labradorite

Scratches glass

Quartz / Amethyst / Citrine

Scratches steel

Topaz

Scratches quartz

Corundum (Ruby / Sapphire)

Scratches topaz

Diamond

Scratches everything — hardest natural substance