Organic (Paper And Cellulose)

Limestone

Calcium Carbonate (CaCO3)

Polished banded agate (probable)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide inclusions

Polished dark agate or jasper pebble

Microcrystalline quartz (SiO₂), likely chalcedony with iron-oxide inclusions

Polished gray stone, likely quartzite or river-worn granite

Tentatively quartzite (mostly microcrystalline SiO₂); exact identification is uncertain from the photograph

Polished brown pebble

Likely altered basalt or mafic volcanic rock; exact identification is uncertain from the photograph

Polished fossiliferous agate

Chalcedony (microcrystalline SiO₂), likely containing fossil coral or stromatoporoid structures

Rounded granite pebble

Granite; chiefly quartz, feldspar, and mica

Dyed tumbled stone, likely chalcedony or quartz

Microcrystalline quartz (SiO₂), probably dyed magenta

Limestone

Calcareous sedimentary rock (CaCO3)

Milky quartz pebble

Quartz, silicon dioxide (SiO₂)

Quartz geode (likely chalcedony-lined geode)

Silica geode: microcrystalline quartz/chalcedony with drusy quartz (SiO₂), possibly iron-oxide staining

Polished pink chalcedony (likely pink agate/geode)

Microcrystalline quartz, SiO₂; chalcedony with iron-bearing inclusions and possible druzy quartz

Slag Glass (Cullet)

Amorphous Silica (man-made), primarily SiO2 with trace metal oxides

Limestone

Calcium Carbonate (CaCO3)

Orange Quartzite (or Iron-Stained Quartz)

Silicon Dioxide (SiO2) with Iron Oxide impurities (Fe2O3)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Marble

Recrystallized Calcite (CaCO3)

Polished blue agate geode slice

Chalcedony (microcrystalline quartz), SiO₂, with possible quartz/drusy lining and iron-oxide coloration

Rounded dark river cobble, likely basalt

Basalt; fine-grained mafic volcanic rock composed mainly of plagioclase and pyroxene, commonly with olivine

Agate (specifically Lace Agate or Banded Agate)

Silicon Dioxide (SiO2)

Honey Calcite

Calcite (Calcium Carbonate - CaCO3)

Limestone (Chalk / Calcite Rock)

Calcium Carbonate (CaCO3)

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

Dyed and polished agate slice

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

Banded limestone or marble pebble

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

Polished red granite or rhyolite pebble

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

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)

Mica (Biotite or Phlogopite variety)

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

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