Mineral, Possibly Rock Fragment Containing A Mineral

Polymictic conglomerate (possibly impact breccia)

Lithified polymictic conglomerate/breccia; clasts appear mainly mafic volcanic rock, with quartz- or feldspar-rich fragments in a dark matrix

Weathered iron-rich stone, possibly sandstone or ironstone

Indeterminate; likely quartz-rich sandstone with iron-oxide cement, possibly hematite/goethite

Unidentified metallic-looking mineral fragment

Indeterminate; possible galena, magnetite, or metal-rich sulfide/ore fragment

Weathered gray stone fragment

Undetermined; possibly limestone or sandstone

Metamorphic schist, possibly chlorite–biotite schist

Schist; composition likely quartz, feldspar, mica (biotite/muscovite), and chlorite

Small brown mineral specimen, possibly mica-bearing rock

Unidentified from the image; exact mineral species cannot be determined at this scale

Unidentified rough mineral/rock fragment

Indeterminate from image; possibly quartz-rich material or weathered carbonate rock

Fossiliferous Limestone

Sedimentary rock containing Indeterminate Fossil remains (likely Crinoid stem or Bryozoan fragment)

Basalt fragment

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

Small dark metallic-looking rock fragment

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

Small metallic-looking rock fragment

Uncertain; possibly galena-bearing ore or mica-rich schist

Weathered golden-brown mineral/rock fragment

Indeterminate from image; possibly iron-stained quartz, feldspar, or a sulfide-bearing rock

Breccia

Breccia (Sedimentary Clastic Rock)

Fossilized tooth, likely a mammalian tooth fragment

Indeterminate fossil tooth; possibly an ungulate or carnivoran tooth

Blue-green mineral fragment, possibly turquoise

Unidentified copper-bearing mineral; turquoise is CuAl₆(PO₄)₄(OH)₈·4H₂O

Unidentified yellow-orange mineral fragment

Possibly iron-stained quartz, calcite, or citrine; identification is uncertain from the image

Fossilized Bone Chunk

Permineralized Vertebrate Bone (indeterminant)

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Weathered fossiliferous limestone

Calcitic limestone, predominantly calcium carbonate (CaCO₃), possibly bioclastic limestone

Likely weathered sandstone or iron-stained sedimentary pebble

Indeterminate clastic sedimentary rock; possibly quartz-rich sandstone

Unable to identify - Image contains non-geological items

Small green mineral specimen, possibly aventurine or serpentine

Uncertain; likely quartz-bearing aventurine (SiO₂) or serpentine-group mineral

Blue-gray mineral/rock fragment

Indeterminate; possibly azurite-bearing material, blue chalcedony, or dyed/coated stone

Black-and-white bicolored pebble

Likely basalt with a pale felsic or carbonate coating/inclusion; exact identification requires testing

Likely garnet-bearing rock (possibly almandine garnet in dark matrix)

Garnet, probably almandine (Fe₃Al₂(SiO₄)₃); host rock is not identifiable from this image

Sandstone (likely Ferruginous)

Sandstone (SiO2 with iron oxides)

Weathered rock fragment, possibly granite or metamorphic stone

Indeterminate; likely quartz–feldspar–mica aggregate (granite-like), but image resolution prevents reliable identification

Weathered quartz-rich rock, possibly quartzite or granite fragment

Uncertain; likely quartz–feldspar aggregate, possibly altered granite or quartzite

Quartz-rich rock fragment

Likely milky quartz with feldspar and possible mica; exact rock type is indeterminate from the image

Unidentified weathered rock fragments

Likely mixed quartz- and feldspar-bearing silicate material; exact identification requires testing

Likely calcite fragment

Calcite (CaCO₃), possibly limestone or marble

Weathered quartz-bearing rock, possibly serpentine or altered ultramafic rock

Provisional identification: serpentinite or chlorite–quartz schist; exact composition requires testing

Asphalt (Bituminous Concrete)

Composite material (bitumen binder with mineral aggregate)

Small water-worn pebble, likely quartz-rich

Rock fragment of uncertain composition; possibly quartzite or chert

Weathered quartz-rich pebble

Mostly microcrystalline quartz (SiO₂), possibly quartzite or chalcedony with iron-oxide staining

Uncertain pale mineral/rock fragment

Indeterminate; possibly calcite-rich material or a light-colored carbonate rock

Quartz-bearing rock, possibly pegmatite

Likely quartz and feldspar with dark mica or other accessory minerals; exact rock type is uncertain from the image

Weathered fossiliferous limestone

Calcitic limestone; predominantly CaCO₃, possibly containing a fossil mold or shell fragment

Small tan rock fragment

Indeterminate; possibly quartz-rich sandstone or iron-stained quartz

Likely small iron-rich concretion or weathered mineral fragment

Indeterminate; possibly limonite/goethite-bearing material with quartz or feldspar

Weathered brown rock fragment, possibly iron-rich sandstone or altered basalt

Indeterminate; likely an iron-oxide–stained silicate rock

Amethyst geode or druzy quartz specimen

Quartz, SiO₂; purple coloration is typically caused by iron-related defects and irradiation