Mineral, Possibly Rock Fragment Containing A Mineral

Sandstone (with potential fossil inclusions)

Clastic sedimentary rock (primarily SiO2)

Basalt (likely vesicular basalt)

Basalt; chiefly plagioclase feldspar, pyroxene, and often olivine

Graphite-rich metamorphic rock (probable graphite schist)

Graphite schist; predominantly graphite (C) with quartz and mica

Weathered quartz-rich rock, possibly vein quartz

Quartz-rich rock; predominantly silicon dioxide (SiO₂), exact rock type uncertain from the photograph

Granite

Intrusive Igneous Rock

Weathered Sandstone with Algae Growth

Arenite

Weathered quartz-rich pebble

Likely milky quartz (SiO₂), possibly a quartz-rich vein fragment

Small brown mineral/rock fragment

Uncertain; possibly iron-oxide-stained quartz, jasper, or a weathered ironstone fragment

Weathered iron-rich rock, possibly laterite or limonite-bearing sandstone

Iron oxides/hydroxides, chiefly limonite/goethite (FeO(OH)·nH₂O), with a probable silicate or clay matrix

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 cement)

Sandstone with Iron Staining

Arenite with Limonite/Hematite inclusions (SiO2 + Fe2O3/FeO(OH))

Sandstone

Arenite (SiO2 primarily)

Small brown quartz-rich pebble, possibly chert or jasper

Microcrystalline quartz (SiO₂), tentative

Likely raw metallic mineral specimen

Unidentified; possibly galena-bearing ore or magnetite-rich rock

Metallic sulfide ore fragment, possibly pyrite-bearing rock

Indeterminate; likely pyrite (FeS₂) in a sulfide-rich matrix

Likely weathered iron-rich rock fragment

Probably limonite/goethite-bearing material; exact identification requires testing

Small gray rock fragment

Indeterminate; possibly quartz-rich granite, chert, or concrete-like silicate material

Likely quartz-rich rock fragment

Quartz (SiO₂), possibly in a feldspar-bearing granite or pegmatite matrix

Vesicular basalt (likely scoriaceous basalt)

Basalt; primarily plagioclase, pyroxene, and iron-rich olivine, with abundant vesicles

Sandstone

Sandstone (composed predominantly of Quartz, SiO2)

Banded quartz-rich rock (possibly pegmatite)

Likely quartz–feldspar pegmatite; identification is tentative from the photo

Pebble

Clast (specifically a granule or small pebble)

Green chalcedony (possibly jade or serpentine)

Microcrystalline quartz, SiO₂; exact identification is uncertain from the image

Sandstone (likely Arkosic or Lithic Sandstone)

Arenite (SiO2 based with mineral inclusions)

Granite with Epidote

Granite, containing quartz, feldspar, and epidote

Weathered iron-rich rock fragment

Indeterminate; likely limonite/goethite-bearing rock, possibly altered basalt or ironstone

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

Quartz, silicon dioxide (SiO₂); exact identification is limited by the small photograph

Sandstone (Painted)

Arenite (primarily SiO2)

Fossiliferous limestone, likely coral or shell-rich fragment

Calcite (CaCO₃), commonly bioclastic limestone containing fossilized marine organisms

Blue crystal/mineral specimen (possibly blue quartz or dyed stone)

Uncertain from photograph; possible quartz, SiO₂, or a blue copper-bearing mineral

Clear quartz chips

Quartz (silicon dioxide, SiO₂)

Likely polished/tumbled dark mineral or glassy rock fragment

Indeterminate from image; possibly hornblende, schorl tourmaline, or obsidian

Polished brown mineral fragment, likely quartz-rich iron-stained material

Possibly quartz (SiO₂) with iron-oxide inclusions; exact identification is uncertain from the image

Likely tumbled quartz or feldspar pebble

Indeterminate; possibly quartz (SiO₂) or potassium feldspar (KAlSi₃O₈)

Sandstone (likely Fossiliferous Sandstone)

Clastic sedimentary rock (primarily SiO2)

Shale fragment

Shale (Laminated Mudstone)

Small weathered rock fragment

Indeterminate; possibly limestone or altered volcanic rock

Probable rough basalt or mafic igneous fragment

Fine-grained basalt, likely plagioclase–pyroxene–olivine aggregate

Weathered quartz-rich rock, likely milky quartz with iron staining

Quartz (SiO₂), possibly quartz vein material or quartzite

Vesicular Basalt or Porphyritic Rhyolite

Extrusive Igneous Rock

Tumbled reddish-brown stone, possibly jasper or quartzite

Uncertain; likely microcrystalline quartz (SiO₂), potentially iron-stained jasper

Small reddish-brown mineral fragment, likely quartz-bearing rock

Indeterminate; possibly iron-stained quartz or feldspar-rich stone