Sedimentary (Processed Mineral Product)

Blue Kyanite

Kyanite (Al2SiO5)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Polished sodalite pendant

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂, likely with minor albite or nepheline

Iron-rich weathered rock, possibly limonite/goethite-bearing ore

Limonite (hydrated iron oxides; chiefly goethite, FeO(OH), with hematite and other oxides possible)

Rhodonite

Inosilicate (Mn,Fe,Mg,Ca)SiO3

Rodonite

Rhodonite (MnSiO3)

Green sea glass (likely bottle glass)

Human-processed soda–lime silicate glass; not a natural mineral or rock

Amethyst ring

Amethyst, purple quartz (SiO₂), likely set with diamond or other accent stones

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz and Mixed Minerals

Silicon Dioxide (SiO2)

Quartz-rich pegmatite with mica

Granitic pegmatite; mainly quartz (SiO₂), feldspar, and muscovite/biotite mica, with possible sulfide or iron-oxide staining

Blue slag glass / industrial glass fragment

Artificial silicate glass, composition variable; likely copper- or cobalt-colored furnace slag

Tumbled amethyst

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

Yellow calcite (rough crystal)

Calcite, CaCO₃

Iron-rich metamorphic rock, possibly micaceous schist

Biotite–quartz schist or iron-rich phyllite (tentative visual identification)

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Quartz pebble

Silicon dioxide (SiO2)

Limonite-goethite ironstone specimen

Goethite (α-FeO(OH)) with limonite, quartz, and iron oxides

Opalite

Synthetic Opalized Glass / Man-made Glass

Orange Calcite

Calcium Carbonate (CaCO3)

Rock and Mineral Collection

Mixed Geological Specimens

Sodalite

Sodalite (Na8(Al6Si6O24)Cl2)

Quartz Pebble

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Limestone

Calcium carbonate (CaCO3)

Green glassy gemstone-like specimen

Likely synthetic glass or treated quartz; exact identification requires testing

Faceted diamond gemstone (likely)

Diamond — crystalline carbon, C

Magnetite

Magnetite (Fe3O4)

Weathered iron-rich sandstone or ferruginous pebble

Quartz-rich sandstone with iron-oxide cement; exact identification requires testing

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)

Green aventurine pendant

Quartz variety, SiO₂, colored mainly by fuchsite or other chromium-bearing mica inclusions

Pink Granite

Phaneritic intrusive igneous rock with dominant Alkali Feldspar

Milky Quartz Pebble with Iron Inclusions

Silicon Dioxide (SiO2)

Chert

Microcrystalline quartz (SiO2)

Bentonite Clay

Montmorillonite (Al2H2O12Si4)

Limestone

Limestone (Calcium Carbonate - CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Weathered Sandstone Cobble

Arenite / Quartz Sandstone

Magnetite (lodestone), possibly meteoritic iron

Magnetite, Fe₃O₄; exact identification is uncertain from the image alone

Pyrite

Iron Sulfide (FeS2)