Every stone.
A little discovery.

SPECIMEN 01 / Quartz-rich material

Green Aventurine

Fine mineral inclusions give this green quartz-rich material its speckled, sometimes sparkling appearance.

Composition

SiO₂

Hardness · Mohs

7

Reported reference locality

India

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 02 / Quartz variety

Amethyst

Amethyst is purple quartz. Look for colour zoning: lighter and darker areas can occur within the same piece.

Composition

SiO₂

Hardness · Mohs

7

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 03 / Trade-name rock

Dragon Blood Stone

A trade name used for green-and-red ornamental stone. Colour alone does not establish which minerals make up a particular piece.

Composition

Variable mineral mixture

Hardness · Mohs

Varies

Reported reference locality

Australia

Localities are reference information, not verified provenance for your individual piece.

Trade labels can cover different materials. The photo and name alone cannot confirm mineral identity, composition or treatment.

A visual comparison guide, not a laboratory identification.

SPECIMEN 04 / Rock / mineral aggregate

Lapis Lazuli

Lapis lazuli is a rock, not a single mineral. Its blue colour may be interrupted by white calcite and small golden pyrite flecks.

Composition

Lazurite, calcite, pyrite and other minerals

Hardness · Mohs

5–6

Reported reference locality

Afghanistan

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 05 / Quartz variety

Citrine

Citrine is yellow to orange quartz. Much commercial citrine is heat-treated amethyst; appearance alone cannot confirm whether a piece is untreated.

Composition

SiO₂

Hardness · Mohs

7

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

Treatment status of the supplied batch has not been confirmed. Heat-treated material must not be described as untreated.

A visual comparison guide, not a laboratory identification.

SPECIMEN 06 / Quartz-rich rock

Mookaite Jasper

Mookaite is an ornamental name for colourful silica-rich stone. The reference piece shows warm yellow, cream and red tones.

Composition

Mainly SiO₂

Hardness · Mohs

About 7

Reported reference locality

Australia

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 07 / Quartz variety

Rose Quartz

Rose quartz is the pink variety of quartz. Many pieces are translucent and cloudy rather than perfectly clear.

Composition

SiO₂

Hardness · Mohs

7

Reported reference locality

Madagascar

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 08 / Volcanic glass

Obsidian

Obsidian forms when lava cools into natural glass. Fresh breaks can have curved, shell-like surfaces and sharp edges.

Composition

Silica-rich glass; variable composition

Hardness · Mohs

About 5–5.5

Reported reference locality

Mexico

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 09 / Chalcedony variety

Moss Agate

Moss agate contains branching mineral inclusions that can resemble moss. These patterns are minerals, not preserved plants.

Composition

Mainly SiO₂, with mineral inclusions

Hardness · Mohs

6.5–7

Reported reference locality

India

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 10 / Rock / mineral aggregate

Unakite

Unakite combines contrasting mineral grains, commonly green epidote, pink feldspar and quartz. Its mottled pattern differs from piece to piece.

Composition

Feldspar, epidote and quartz

Hardness · Mohs

Varies by component

Reported reference locality

USA

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 11 / Quartz variety

Clear Quartz

Clear quartz is colourless quartz. A specimen may be transparent or contain cloudy areas, internal fractures and inclusions.

Composition

SiO₂

Hardness · Mohs

7

Documented mineral localities (examples)

Austria, France, Italy, Switzerland, Brazil

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 12 / Silicate mineral

Sodalite

Sodalite is commonly blue, with white mineral patches or veins in ornamental specimens. Blue colour alone does not distinguish it from every similar stone.

Composition

Na₈Al₆Si₆O₂₄Cl₂

Hardness · Mohs

5.5–6

Documented mineral localities (examples)

Norway, Italy, Canada, USA, Russia

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 13 / Quartz-rich material

Tiger's Eye

Tiger’s eye is known for a shifting band of reflected light, called chatoyancy. This effect is usually clearer on a smooth surface than on rough material.

Composition

Mainly SiO₂

Hardness · Mohs

7

Reported reference locality

China

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 14 / Quartz-rich rock

Red Jasper

Red jasper is an opaque, fine-grained silica-rich material. Its red body colour may include pale veins or differently coloured patches.

Composition

Mainly SiO₂

Hardness · Mohs

About 7

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 15 / Feldspar variety

Peach Moonstone

Peach moonstone is a colour name for peach-toned feldspar. Some pieces show a soft floating sheen when the viewing angle changes.

Composition

KAlSi₃O₈; feldspar composition can vary

Hardness · Mohs

6–6.5

Reported reference locality

Madagascar

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 16 / Plagioclase feldspar

Labradorite

Labradorite can show flashes of colour called labradorescence. The flash depends on the angle of light and may be subtle on rough pieces.

Composition

Solid solution between NaAlSi₃O₈ and CaAl₂Si₂O₈

Hardness · Mohs

6–6.5

Reported reference locality

Madagascar

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 17 / Borate mineral

Howlite

Howlite is usually white and often occurs in nodules. Dark veins may cross ornamental pieces; dyed material can have a very different colour.

Composition

Ca₂B₅SiO₉(OH)₅

Hardness · Mohs

3.5

Documented mineral localities (examples)

Mexico, Canada, USA, Turkey

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 18 / Lithium-mica material

Lepidolite

Lepidolite is a name used for lithium-rich mica material. Its small flakes can create a pearly, layered appearance.

Composition

K(Li,Al)₃(Si,Al)₄O₁₀(F,OH)₂; variable

Hardness · Mohs

2.5–4

Documented mineral localities (examples)

Brazil, Madagascar, Canada, USA, Russia

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 19 / Microcline feldspar

Amazonite

Amazonite is green to blue-green microcline feldspar. Pale streaks or patches may interrupt its body colour.

Composition

KAlSi₃O₈

Hardness · Mohs

6–6.5

Reported reference locality

Madagascar

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 20 / Trade-name rock

Yooperlite

Yooperlite is a trade name for sodalite-bearing rock. The mineral mixture, rather than one chemical formula, defines the material.

Composition

Sodalite-bearing rock; variable mixture

Hardness · Mohs

Varies by component

Reported reference locality

USA

Localities are reference information, not verified provenance for your individual piece.

Trade labels can cover different materials. The photo and name alone cannot confirm mineral identity, composition or treatment.

A visual comparison guide, not a laboratory identification.

SPECIMEN 21 / Feldspar material

Moonstone

Moonstone is feldspar known for adularescence: a soft glow that appears to move below the surface. Not every rough fragment shows this clearly.

Composition

Feldspar mixture; commonly orthoclase and albite

Hardness · Mohs

6–6.5

Reported reference locality

India

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 22 / Chalcedony variety

Bloodstone

Bloodstone is typically dark green chalcedony with contrasting red areas. The amount and distribution of red vary between specimens.

Composition

Mainly SiO₂, with inclusions

Hardness · Mohs

6.5–7

Reported reference locality

Madagascar

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 23 / Volcanic glass

Mahogany Obsidian

Mahogany obsidian is a brown-and-black variety of natural volcanic glass. Its colour pattern and glassy fracture are useful comparison features.

Composition

Silica-rich glass; variable composition

Hardness · Mohs

About 5–5.5

Reported reference locality

Mexico

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 24 / Mineral aggregate

Ruby in Zoisite

Ruby in zoisite combines red corundum with green zoisite-rich material. A mixed specimen has different properties in its different mineral grains.

Composition

Zoisite with corundum; other minerals may occur

Hardness · Mohs

Varies by component

Reported reference locality

Tanzania

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 25 / Quartz-rich material

Yellow Aventurine

Yellow aventurine is a yellow-toned quartz-rich material. Fine inclusions may create a speckled appearance or a gentle sparkle.

Composition

Mainly SiO₂

Hardness · Mohs

7

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 26 / Quartz-rich trade material

Ocean Jasper

Ocean jasper is an ornamental trade name associated with patterned silica-rich stone. Rounded spots and colour combinations can vary widely.

Composition

Mainly silica; mineral mixture varies

Hardness · Mohs

About 7 if quartz-rich

Reported reference locality

Madagascar

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 27 / Trade-name material

Zebra Stone

Zebra Stone is used for more than one banded ornamental rock. A striped appearance is a visual clue, not a mineral identification.

Composition

No single formula established

Hardness · Mohs

Not established

Reported reference locality

Australia

Localities are reference information, not verified provenance for your individual piece.

Trade labels can cover different materials. The photo and name alone cannot confirm mineral identity, composition or treatment.

A visual comparison guide, not a laboratory identification.

SPECIMEN 28 / Trade-name material

Green Strawberry Quartz

Green Strawberry Quartz is a commercial name. Compare its green colour and inclusions, but do not assume that the name proves composition or treatment status.

Composition

Confirm the material supplied

Hardness · Mohs

Not established

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

Trade labels can cover different materials. The photo and name alone cannot confirm mineral identity, composition or treatment.

A visual comparison guide, not a laboratory identification.

SPECIMEN 29 / Hydrated silica / mineraloid

Pink Opal

Pink opal is usually common opal, which lacks the rainbow play-of-colour of precious opal. It contains water within its silica structure.

Composition

SiO₂·nH₂O

Hardness · Mohs

5–6.5

Reported reference locality

Peru

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 30 / Halite

Himalayan Salt

The main mineral in Himalayan salt is halite. A collection specimen is for observation and must not be treated as food-grade salt.

Composition

NaCl

Hardness · Mohs

2–2.5

Reported reference locality

Pakistan

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 31 / Calcite trade variety

Orchid Calcite

Orchid Calcite is a trade colour name. Calcite is a relatively soft carbonate; colour or associated minerals do not change calcite’s reference hardness of 3.

Composition

CaCO₃; associated minerals may be present

Hardness · Mohs

3 for calcite

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 32 / Quartz-rich material

Red Aventurine

Red aventurine is a red to orange quartz-rich material. Fine inclusions contribute to its colour and may create small reflective points.

Composition

Mainly SiO₂

Hardness · Mohs

7

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 33 / Halide mineral

Fluorite

Fluorite occurs in many colours and can show distinct colour bands. Cubic crystals and smooth cleavage surfaces may appear in specimens.

Composition

CaF₂

Hardness · Mohs

4

Documented mineral localities (examples)

France, Switzerland, Mexico, Canada, USA

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 34 / Trade-name rock

Dalmatian Stone

Dalmatian Stone is a spotted rock, not a true jasper. A published study identified feldspar and quartz with dark arfvedsonite spots in the samples examined.

Composition

Feldspar, quartz and amphiboles; a mineral mixture

Hardness · Mohs

Not established

Geographic origin

Provenance not established in the cited study

Localities are reference information, not verified provenance for your individual piece.

Published findings describe the studied samples and do not identify every specimen sold under this trade name.

A visual comparison guide, not a laboratory identification.

SPECIMEN 35 / Quartz-rich material

Blue Aventurine

Blue aventurine is a blue-toned quartz-rich material. Its texture is often granular or speckled rather than uniformly transparent.

Composition

Mainly SiO₂

Hardness · Mohs

7

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 36 / Trade-name quartz material

Strawberry Quartz

Strawberry Quartz is a trade name for pink or red included quartz and sometimes look-alike material. The name alone cannot establish authenticity or treatment.

Composition

Usually quartz with inclusions; verify material

Hardness · Mohs

7 if quartz

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

Trade labels can cover different materials. The photo and name alone cannot confirm mineral identity, composition or treatment.

A visual comparison guide, not a laboratory identification.

SPECIMEN 37 / Gypsum variety

Selenite

Selenite is a variety of gypsum. Fibrous gypsum sold under this name is often called satin spar; both are much softer than quartz.

Composition

CaSO₄·2H₂O

Hardness · Mohs

1.5–2

Documented mineral localities (examples)

Austria, France, Italy, Switzerland, Mexico

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 38 / Chalcedony variety

Crazy Lace Agate

Crazy lace agate has intricate, folded-looking bands and swirls. These patterns are the main feature to compare with the reference image.

Composition

Mainly SiO₂

Hardness · Mohs

6.5–7

Reported reference locality

Mexico

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 39 / Manganese silicate

Rhodonite

Rhodonite is a pink to red manganese silicate. Ornamental pieces can contain black manganese-oxide veins and patches.

Composition

Mn-rich silicate; Fe, Mg and Ca may substitute

Hardness · Mohs

5.5–6.5

Documented mineral localities (examples)

Italy, Brazil, USA, Australia, Russia

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 40 / Trade-name rock

Kiwi Jasper

Kiwi Jasper is a trade name for pale, often greenish spotted stone. The name does not guarantee that the material is a true jasper.

Composition

Mixed minerals; identity requires confirmation

Hardness · Mohs

Not established

Reported reference locality

Australia

Localities are reference information, not verified provenance for your individual piece.

Trade labels can cover different materials. The photo and name alone cannot confirm mineral identity, composition or treatment.

A visual comparison guide, not a laboratory identification.

SPECIMEN 41 / Apatite-group mineral

Blue Apatite

Blue apatite belongs to the apatite mineral group. It is softer and more easily damaged than similarly coloured quartz or beryl.

Composition

Ca₅(PO₄)₃(F,Cl,OH); group composition varies

Hardness · Mohs

5

Reported reference locality

Madagascar

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 42 / Tourmaline-group mineral

Black Tourmaline

Black tourmaline is commonly schorl. Rough crystals often have a dark surface with lengthwise grooves.

Composition

Commonly schorl: NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Hardness · Mohs

7–7.5

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 43 / Tourmaline-group mineral

Pink Tourmaline

Pink tourmaline is a colour variety within the tourmaline group. Its exact mineral species cannot be determined from pink colour alone.

Composition

Complex borosilicate; species-dependent formula

Hardness · Mohs

7–7.5

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 44 / Oxide mineral

Corundum

Corundum is aluminium oxide and is very hard. Ruby and sapphire are gem varieties, but many corundum specimens are opaque or only partly translucent.

Composition

Al₂O₃

Hardness · Mohs

9

Documented mineral localities (examples)

Madagascar, Canada, USA, Australia, South Africa

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 45 / Beryl variety

Aquamarine

Aquamarine is the blue to greenish-blue variety of beryl. Rough pieces may contain cloudy areas and fractures despite their relatively high hardness.

Composition

Be₃Al₂Si₆O₁₈

Hardness · Mohs

7.5–8

Reported reference locality

Mozambique

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 46 / Sulfide mineral

Pyrite

Pyrite has a brassy metallic appearance. It often forms cubes or other sharply shaped crystals and is chemically different from gold.

Composition

FeS₂

Hardness · Mohs

6–6.5

Documented mineral localities (examples)

Italy, USA, Spain

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 47 / Oxide mineral

Hematite

Hematite is an iron oxide that may appear metallic grey or earthy red. Its surface appearance varies with the form of the specimen.

Composition

Fe₂O₃

Hardness · Mohs

5–6

Documented mineral localities (examples)

Norway, Italy, Switzerland, Brazil, USA

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 48 / Fossil

Ammonite

Ammonites were marine animals with chambered shells. A fossil is preserved biological evidence, not a single mineral with one formula and hardness.

Composition

Shell and replacement minerals vary

Hardness · Mohs

Not one fixed value

Reported reference locality

Madagascar

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 49 / Sulfate mineral

Celestite

Celestite, also called celestine, is a strontium sulfate mineral. Pale blue crystal groups can look delicate and are relatively soft.

Composition

SrSO₄

Hardness · Mohs

3–3.5

Documented mineral localities (examples)

Norway, Italy, Madagascar, Mexico, Canada

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 50 / Gypsum or baryte aggregate

Desert Rose

Desert rose describes a rosette-shaped crystal aggregate, not one mineral species. Gypsum and baryte can both form this shape, so composition needs confirmation.

Composition

Depends on the mineral forming the rose

Hardness · Mohs

Varies; gypsum about 2

Reported reference locality

Mongolia

Localities are reference information, not verified provenance for your individual piece.

Trade labels can cover different materials. The photo and name alone cannot confirm mineral identity, composition or treatment.

A visual comparison guide, not a laboratory identification.

SPECIMEN 51 / Carbonate mineral

Aragonite

Aragonite and calcite have the same chemical composition but different crystal structures. Aragonite can form radiating or clustered crystals.

Composition

CaCO₃

Hardness · Mohs

3.5–4

Documented mineral localities (examples)

Austria, Italy, Mexico, USA, Namibia

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 52 / Quartz variety

Smoky Quartz

Smoky quartz is brown to grey quartz. Its smoky colour may be light and transparent or dark enough to obscure the interior.

Composition

SiO₂

Hardness · Mohs

7

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 53 / Grown display crystal

Bismuth

The stepped, rainbow-coloured bismuth form shown here is typically grown by people. Its geometric appearance should not be presented as proof of a naturally mined crystal.

Composition

Bi

Hardness · Mohs

2–2.5

Production location in supplied list

China

Localities are reference information, not verified provenance for your individual piece.

Manufactured or grown display material; not presented here as a naturally mined crystal.

A visual comparison guide, not a laboratory identification.

SPECIMEN 54 / Carbon-rich rock

Shungite

Shungite is a name for carbon-rich rock. A single carbon or fullerene formula cannot represent the whole rock or establish the composition of a supplied piece.

Composition

Carbon plus variable minerals

Hardness · Mohs

Varies by composition

Reported reference locality

Russia

Localities are reference information, not verified provenance for your individual piece.

Trade labels can cover different materials. The photo and name alone cannot confirm mineral identity, composition or treatment.

A visual comparison guide, not a laboratory identification.

SPECIMEN 55 / Copper carbonate hydroxide

Azurite

Azurite is a deep blue copper mineral. It can occur alongside green malachite, creating strong colour contrasts in one specimen.

Composition

Cu₃(CO₃)₂(OH)₂

Hardness · Mohs

3.5–4

Documented mineral localities (examples)

France, Italy, Mexico, USA, Namibia

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 56 / Aluminium silicate

Kyanite

Kyanite often forms long, blade-like crystals. Its hardness varies with crystal direction, so one number does not fully describe it.

Composition

Al₂SiO₅

Hardness · Mohs

About 5.5 to 7, depending on direction

Documented mineral localities (examples)

Austria, Norway, Italy, Switzerland, Brazil

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 57 / Garnet-group mineral

Garnet

Garnet is a group of minerals with related structures. Red is familiar, but garnets occur in other colours and do not all share one chemical formula.

Composition

X₃Y₂(SiO₄)₃; elements vary by species

Hardness · Mohs

6.5–7.5

Reported reference locality

Madagascar

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 58 / Copper carbonate hydroxide

Malachite

Malachite is a green copper mineral. Bands and rounded growth patterns are common, though the appearance depends on how a specimen is exposed or finished.

Composition

Cu₂(CO₃)(OH)₂

Hardness · Mohs

3.5–4

Documented mineral localities (examples)

France, Mexico, USA, Namibia, Australia

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 59 / Spodumene variety

Kunzite

Kunzite is pink to violet spodumene. Its colour can appear different with viewing direction, and it should be protected from prolonged strong light.

Composition

LiAlSi₂O₆

Hardness · Mohs

6.5–7

Reported reference locality

Mozambique

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 60 / Transparent calcite

Iceland Spar

Iceland spar is transparent calcite. Its strong double refraction can make an image seen through a clear piece appear doubled.

Composition

CaCO₃

Hardness · Mohs

3

Documented mineral localities (examples)

Mexico, USA, Namibia, Russia, Germany

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 61 / Quartz crystal aggregate

Amethyst Cluster

An amethyst cluster is a group of purple quartz crystals growing together. It is a growth form of amethyst, not a separate mineral species.

Composition

SiO₂

Hardness · Mohs

7

Reported reference locality

Brazil

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 62 / Manufactured silicon carbide

Carborundum

Carborundum is silicon carbide. The large iridescent display clusters sold under this name are manufactured material, rather than ordinary natural crystal specimens.

Composition

SiC

Hardness · Mohs

About 9–9.5

Production location in supplied list

China

Localities are reference information, not verified provenance for your individual piece.

Manufactured or grown display material; not presented here as a naturally mined crystal.

A visual comparison guide, not a laboratory identification.

SPECIMEN 63 / Aragonite trade variety

Blue Aragonite

Blue Aragonite is a colour-based trade label. Aragonite’s mineral properties apply only after the material has been correctly identified.

Composition

CaCO₃ if identified as aragonite

Hardness · Mohs

3.5–4 if aragonite

Reported reference locality

Morocco

Localities are reference information, not verified provenance for your individual piece.

Trade labels can cover different materials. The photo and name alone cannot confirm mineral identity, composition or treatment.

A visual comparison guide, not a laboratory identification.

SPECIMEN 64 / Aragonite trade variety

Pink Aragonite

Pink Aragonite is a colour-based trade label. Similar-looking carbonate materials need more than colour alone for a reliable identification.

Composition

CaCO₃ if identified as aragonite

Hardness · Mohs

3.5–4 if aragonite

Reported reference locality

Morocco

Localities are reference information, not verified provenance for your individual piece.

Trade labels can cover different materials. The photo and name alone cannot confirm mineral identity, composition or treatment.

A visual comparison guide, not a laboratory identification.

SPECIMEN 65 / Manufactured glass in this list

Opalite

The supplied list identifies this opalite as manufactured glass. Its milky glow does not make it natural opal or natural moonstone.

Composition

Glass; formulation varies

Hardness · Mohs

Varies by formulation

Production location in supplied list

China

Localities are reference information, not verified provenance for your individual piece.

Manufactured or grown display material; not presented here as a naturally mined crystal.

A visual comparison guide, not a laboratory identification.

SPECIMEN 66 / Trade-name material

Lemon Jade

Lemon Jade is a commercial colour name. It does not by itself confirm jadeite or nephrite; the mineral identity should be stated by the supplier.

Composition

Identity not established by the name

Hardness · Mohs

Not established

Reported reference locality

China

Localities are reference information, not verified provenance for your individual piece.

Trade labels can cover different materials. The photo and name alone cannot confirm mineral identity, composition or treatment.

A visual comparison guide, not a laboratory identification.

SPECIMEN 67 / Copper iron sulfide

Bornite

Bornite can develop colourful tarnish. Peacock Ore is also used for other, sometimes treated, sulfides, so an iridescent surface does not prove that a piece is bornite.

Composition

Cu₅FeS₄

Hardness · Mohs

3–3.25

Documented mineral localities (examples)

Austria, USA, Australia, England, South Africa

Localities are reference information, not verified provenance for your individual piece.

Trade labels can cover different materials. The photo and name alone cannot confirm mineral identity, composition or treatment.

A visual comparison guide, not a laboratory identification.

SPECIMEN 68 / Volcanic rock

Lava Stone

Lava Stone is a broad name for volcanic rock. Gas bubbles can leave visible holes, but a porous texture alone does not specify an exact rock composition.

Composition

Variable mineral mixture

Hardness · Mohs

Not one fixed value

Reported reference locality

China

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 69 / Phosphate mineral

Purpurite

Purpurite is a manganese-rich phosphate that can appear purple. Its colour and associated minerals vary between specimens.

Composition

(Mn,Fe)PO₄

Hardness · Mohs

4–4.5

Documented mineral localities (examples)

France, USA, Namibia, Australia, Sweden

Localities are reference information, not verified provenance for your individual piece.

A visual comparison guide, not a laboratory identification.

SPECIMEN 70 / Epidote-group silicate

Epidote

Epidote is a calcium-aluminium-iron silicate, often pistachio green. Prismatic crystals may have lengthwise grooves; granular or massive pieces can lack obvious crystal faces.

Composition

Ca₂Al₂(Fe³⁺,Al)(SiO₄)(Si₂O₇)O(OH)

Hardness · Mohs

6–7

Documented example localities

Austria, France, Norway, Italy, USA, Pakistan and Namibia

Localities are reference information, not verified provenance for your individual piece.

The reference photograph shows an epidote specimen from Canta, Lima, Peru. This is the photograph’s locality, not verified provenance for your supplied piece.

A visual comparison guide, not a laboratory identification.