Sedimentary Rock Or Mineral (Depending On Origin And Purity)

Pink Granite

Phaneritic intrusive igneous rock (Feldspar-Quartz-Mica)

Fluorite (Rainbow Fluorite)

Calcium Fluoride (CaF2)

Jasper with Quartz Vein

Silicon Dioxide (SiO2) with impurities

Tumbled amethyst

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

Hematitic Sandstone

Sandstone with Iron Oxide (Hematite) staining

Banded dark pebble (likely gneiss or banded metamorphic rock)

Indeterminate from the image; possibly banded gneiss

Small dark metallic-looking rock fragment

Undetermined; possibly iron oxide-rich material or a metallic mineral

Shatter Cone

Impactite (Shatter Cone texture)

Ruby

Corundum (Al2O3 with Chromium trace)

Pyrite-bearing quartz rock

Pyrite (FeS₂) in quartz-rich matrix, possibly with mica or chlorite

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Likely quartz-rich rock (possibly milky quartz or quartzite)

Quartz-rich aggregate, predominantly silicon dioxide (SiO₂); exact identification is uncertain from the image

Placer Gold Nugget

Native Gold (Au)

Raw yellow chalcedony or quartz-bearing rock

Microcrystalline silica, SiO₂ (likely chalcedony/quartz; exact identification requires testing)

Likely iron-rich rock or metallic mineral fragment

Uncertain; possibly limonite/goethite-rich material or weathered iron meteorite fragment

Quartz (Chalcedony)

Silicon Dioxide (SiO2)

Manganese Dendrite on Siltstone

Manganese Oxide (pyrolusite or psilomelane) Dendrites

Blue-green opal, likely polished common or synthetic opal

Opal (hydrated amorphous silica, SiO₂·nH₂O); identification from the image is uncertain

Quartz (Grain)

Silicon Dioxide (SiO2)

Gold ring with a dark, possibly gemstone setting

Gold alloy; the dark setting is not identifiable from the image

Rough ruby-bearing corundum (identification uncertain)

Corundum (Al₂O₃), possibly ruby; the image alone cannot confirm ruby or distinguish it from other red-purple minerals.

Fossilized cylindrical shell or bone fragment

Indeterminate biogenic carbonate or phosphatic fossil; possible fragment of a tubular shell (e.g., scaphopod) or hollow bone

Water-worn brown stone, likely basalt or chert

Indeterminate; possible fine-grained basalt (plagioclase–pyroxene) or ferruginous chert (microcrystalline SiO₂)

Ruby

Corundum (Al2O3 with Chromium traces)

Honey-colored quartz-rich rock, possibly yellow chalcedony or quartzite

Quartz/chalcedony, SiO₂; exact identification is uncertain from the photograph

Ferruginous Sandstone with Quartz Inclusions

Clastic Sedimentary Rock (Iron-rich Sandstone)

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Quartz-rich rock fragment

Unidentified quartz–feldspar-rich rock; exact lithology cannot be determined from the image

Granite pebble

Granite, a coarse-grained felsic intrusive igneous rock

Backlit translucent mineral specimen, possibly amber or orange calcite

Undetermined; visual appearance alone cannot distinguish amber from calcite or other translucent minerals

Weathered iron-rich stone, likely ironstone or hematite-bearing chert

Goethite–hematite-rich ironstone; possibly ferruginous chert (FeO(OH)/Fe₂O₃ with silica)

Shungite (or Black Onyx / Obsidian)

Amorphous Carbon (Shungite) / SiO2 (Onyx/Obsidian)

River Rock

Sedimentary clast

Chert

Microcrystalline Quartz (SiO2)

Blue Sapphire

Corundum (Al2O3) with traces of Iron and Titanium

Chalk

Calcium Carbonate (CaCO3)

Weathered stone nodule or concretion

Unidentified lithic concretion; composition cannot be determined from the image

Unknown Organic Object (likely a berry or fruit)

Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.

Marble

Metamorphosed Limestone (CaCO3)

Emerald

Beryl (Be3Al2(SiO3)6)

Sandstone Pebble (Quartzite-rich)

Clastic Terrigenous Sedimentary Rock (SiO2 dominant)

Weathered quartz-rich rock, likely granite or granitic gneiss

Granite/granitic gneiss; chiefly quartz (SiO₂), feldspar, and dark mica or amphibole