Mineral Specimen

Common Opal

Amorphous Hydrated Silica (SiO2·nH2O)

Quartz with Mica (Gneissic or Pegmatitic origin)

Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(F,OH)2)

Staurolite (Fairy Stone)

Staurolite (formula: Fe2+2Al9Si4O23(OH))

Rhodonite-bearing metamorphic rock

Manganese-rich metamorphic rock, chiefly rhodonite (MnSiO₃), with quartz and manganese oxides

Native Copper

Native Copper (Cu)

Weathered iron-rich sandstone or lateritic rock

Quartz-rich sandstone with iron-oxide/hydroxide cement; possible goethite-bearing laterite

Tumbled amethyst

Quartz, crystalline silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Quartz-rich pegmatite (likely milky quartz with feldspar and mica)

Granite pegmatite; chiefly quartz (SiO₂), with feldspar and mica-group minerals

Granite

Granite (a felsic intrusive igneous rock)

Limonite / Goethite Ironstone

FeO(OH)·nH2O (Hydrous iron oxide)

Native copper nugget

Copper (Cu), commonly with cuprite and copper-oxide alteration

Rough Quartz Crystal in Matrix

Silicon Dioxide (SiO2)

Garnet in Schist (Mica Schist with Garnet Inclusion)

Garnetiferous Mica Schist (X3Al2(SiO4)3)

Green calcite (likely)

Calcite, calcium carbonate (CaCO₃)

Pyrite

Iron Sulfide (FeS2)

Specular Hematite and Magnetite Ore

Iron Oxide (Fe2O3 and Fe3O4)

Celestite (Celestine)

Strontium Sulfate (SrSO4)

Pyrite

Iron Sulfide (FeS2)

Ametrine

Silicon Dioxide (SiO2) with impurities of iron

Chert with Quartz Druzy

Microcrystalline Quartz (SiO2) with Drusy Quartz Coating

Fluorite

Calcium Fluoride (CaF2)

Banded iron formation (ironstone)

BIF; hematite–magnetite–quartz/chert assemblage

Quartz Sand / Sandstone grains

Silicon Dioxide (SiO2)

Pegmatite (Granitic Pegmatite with Quartz, Feldspar, and Mica)

Granitic Pegmatite

Copper ore with native copper and quartz/calcite

Malachite–chrysocolla–cuprite-bearing copper ore, likely with quartz or calcite gangue

Blue calcite (probable)

Calcite, calcium carbonate (CaCO₃)

Pyrite

Iron Sulfide (FeS2)

Carved Sea Turtle Figurine (Aventurine / Quartz / Jasper)

Quartz variety (SiO2) / Polycrystalline Quartz Aggregate

Quartz-rich hydrothermal ore rock, likely gold-bearing quartz vein

Milky quartz (SiO₂) with iron-oxide staining and probable sulfide minerals; host rock may be schist or altered granite

Amethyst

Quartz (SiO2) with trace iron impurities

Sodalite-bearing rock, likely sodalite-rich syenite or sodalite in feldspathic matrix

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂, with probable feldspar and accessory minerals

Garnet

Nesosilicate group (e.g., Almandine: Fe3Al2(SiO4)3)

Garnet

Garnet Group (e.g., Almandine Fe3Al2(SiO4)3)

Native Copper with Malachite and Chrysocolla

Native Copper (Cu) with Malachite [Cu2CO3(OH)2] and Chrysocolla [(Cu,Al)2H2Si2O5(OH)4·nH2O]

Black Tourmaline

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

Almandine Garnet

Almandine, Fe3Al2(SiO4)3

Quartz with Pyrite and Iron Staining

Silicon Dioxide (SiO2) with Iron Disulfide (FeS2) inclusions

Quartz-rich breccia or vein quartz fragment

Quartz (SiO₂), likely with iron-oxide staining and attached host rock

Iron-rich quartzite or limonite-bearing rock

Quartzite (SiO₂) with iron oxides/hydroxides, chiefly hematite and goethite

Botryoidal Hematite (Iron Ore)

Iron(III) oxide (Fe2O3)

Tourmaline-bearing pegmatite

Quartz–feldspar pegmatite with black schorl tourmaline; minor mica likely present