Organic (Paper And Cellulose)

Polished malachite

Malachite, Cu₂CO₃(OH)₂

Quartz with Schist/Mica Inclusions

Crystalline Silicon Dioxide (SiO2) with Phyllosilicates

Grey Slate

Foliated Metamorphic Rock (formed by low-grade regional metamorphism of shale or mudstone)

Marble

Recrystallized Calcite (CaCO3)

Pyrite

Iron Sulfide (FeS2)

Marble

Metamorphic rock composed of Recrystallized Carbonate Minerals (chiefly CaCO3)

Fossilized Brachiopod

Phylum Brachiopoda (General mineral composition: Calcite/CaCO₃ or Silica/SiO₂)

Talc (Soapstone variety)

Talc (Hydrated magnesium silicate) - Mg3Si4O10(OH)2

Polished red granite or rhyolite pebble

Likely pink/red granite, composed chiefly of quartz, alkali feldspar, and mica; exact identification requires testing

Banded limestone or marble pebble

Calcite-rich carbonate rock; likely banded marble (CaCO₃)

Dyed and polished agate slice

Agate, a banded microcrystalline variety of chalcedony (SiO₂), commonly quartz with minor impurities

Tumbled gray feldspar-rich stone, possibly granite or quartzite

Indeterminate; likely quartz–feldspar aggregate, potentially fine-grained granite or quartzite

Polished dark agate or jasper sphere

Microcrystalline quartz (chalcedony), SiO₂; possibly iron-rich jasper

Rounded blue-gray stone, likely slate or fine-grained metamorphic rock

Probable slate/phyllite; composition mainly quartz, mica, and feldspar

Limestone Pebble

Calcium Carbonate (CaCO3)

Blue Dyed Agate Geode

Chalcedony (cryptocrystalline Quartz), SiO2

Tumbled Mineral Collection (Amethyst, Celestite, K2 Jasper, Rose Quartz, Ruby in Zoisite, Que Sera Stone)

Mixed Mineral Specimens (Quartz SiO2, Celestite SrSO4, Corundum Al2O3 with Zoisite, etc.)

Sandstone Cobble

Arenite (Secondary classification based on grain size)

Limestone

Calcium Carbonate (CaCO3)

Tumbled milky quartz or pale chalcedony

Quartz, SiO₂; possibly microcrystalline quartz (chalcedony)

Tumbled amber-colored agate or chalcedony

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/agate

Pyrite

Iron Disulfide (FeS2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Banded sandstone pebble

Lithified quartz–feldspar sandstone, possibly iron-oxide-banded arenite

Limestone

Calcium Carbonate (CaCO3)

Pyrite

Iron Sulfide (FeS2)

Polished dark greenstone with quartz vein

Likely chlorite-rich metabasalt or greenschist with a quartz–feldspar vein

Polished black stone, likely basalt or black jasper

Indeterminate; possible fine-grained basalt (plagioclase–pyroxene) or black jasper/microcrystalline quartz

Polished green calcite (often sold as “onyx marble”)

Calcite, CaCO₃; banded crystalline limestone/travertine

Polished orbicular gabbro (likely “leopard-skin” or larvikite-type material)

Gabbro, a coarse-grained mafic plutonic rock; chiefly plagioclase feldspar and pyroxene, with possible olivine/amphibole and iron oxides

Pyrite (Fools Gold)

Iron Sulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Mica (Biotite or Phlogopite variety)

Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)

Polished tiger iron carving

Tiger iron, chiefly hematite–jasper–crocoite/goethite-rich ironstone; composition is uncertain from the image

Limestone

Calcium Carbonate (CaCO3)

Limestone (Brecciated/Recrystallized)

Calcium Carbonate (CaCO3)

Chinese Writing Stone

Porphyritic Basalt (or Andesite) with Feldspar inclusions

Weathered iron-stained quartzite or sandstone cobble

Quartzite, chiefly SiO₂, with iron-oxide staining; possibly ferruginous sandstone

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Rounded quartz-rich river pebble

Likely quartz arenite or chert-derived sandstone; identification is limited from the photograph

Tumbled red jasper

Microcrystalline quartz (chalcedony), predominantly SiO₂, colored by iron oxides

Rounded river pebble, likely weathered basalt or andesite

Fine-grained volcanic rock; composition commonly plagioclase, pyroxene, and minor iron oxides