Sedimentary Or Igneous Fragment

Orange-brown rock fragment, likely iron-stained sandstone

Quartz-rich sandstone with iron-oxide staining (tentative visual identification)

Pale stone fragment (likely limestone)

Likely calcite-rich limestone (CaCO₃); the image is insufficient for a definitive identification

Weathered rock fragment (possibly sandstone)

Indeterminate; likely iron-stained, quartz-rich sandstone

Chert (Flint)

Chert (Microcrystalline or cryptocrystalline Quartz - SiO2)

Sandstone (with garnet granules)

Clastic sedimentary rock (primarily SiO2 with Fe3Al2(SiO4)3 inclusions)

Milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Greenstone

Metamorphosed Mafic Igneous Rock

Weathered granite or granitic gneiss

Granite; chiefly quartz, feldspar, and mica

Smoky Quartz and Chalcedony Geode Fragment

Silicon Dioxide (SiO2)

Volcanic Breccia

Pyroclastic Breccia

Volcanic Breccia

Pyroclastic breccia

Small iron-rich rock fragment (possibly hematite or limonite)

Likely iron oxides/hydroxides: hematite (Fe₂O₃) and/or goethite–limonite; identification is uncertain from the image

Likely quartz-bearing rock fragment

Quartz (SiO₂), possibly with calcite or feldspar

Fossiliferous Limestone

Biogenic Sedimentary Rock (CaCO3)

Unidentified gray rock fragment

Undetermined; the image is too blurred for reliable identification

Unidentified transparent crystal or mineral fragment

Cannot be determined from the image; possible quartz, but not diagnostic

Small pale rock fragment

Unidentified, likely a weathered granitoid or quartz-rich stone; image detail is insufficient for a precise identification

Small rough rock fragment

Undetermined; the image does not show enough detail for a reliable identification

Milky Quartz (Druzy Geode fragment)

Silicon Dioxide (SiO2)

Clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Likely rose quartz fragment

Quartz (SiO₂), likely pale rose quartz

Rounded iron-rich river pebble, likely sandstone or ironstone

Indeterminate ferruginous sandstone/ironstone; exact identification requires closer examination

Quartz Pebble

Silicon Dioxide (SiO2)

Weathered limestone

Calcite-rich limestone, chiefly calcium carbonate (CaCO₃)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Concrete-like aggregate surface with embedded rock fragments

Anthropogenic concrete or exposed aggregate; not a natural rock specimen

Likely rough quartz crystal fragment

Quartz (SiO₂), possibly iron-stained milky quartz

Milky quartz (rough fragment)

Quartz, silicon dioxide (SiO₂)

Granite fragment

Granite, chiefly quartz–feldspar–mica

Likely ironstone or iron-rich rock fragment

Iron-oxide-rich sedimentary material, chiefly hematite (α-Fe₂O₃) and/or goethite (FeO(OH)); exact identification is not possible from the image

Polished dark mineral fragments, likely hematite or magnetite

Hematite (Fe₂O₃) or magnetite (Fe₃O₄)

Likely garnet crystal

Garnet-group silicate; species cannot be determined from the image

Granite fragment

Granite (Felsic Plutonic Rock)

Weathered quartz-rich rock fragment

Likely quartz-bearing feldspathic rock; exact identification requires testing

Likely quartz-rich sandstone

Quartz arenite (tentative; exact identification is not possible from the image alone)

Iron-stained breccia or weathered conglomerate pebble

Clastic sedimentary rock; likely quartz-rich sandstone/breccia with dark mafic or iron-manganese fragments

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with fossil inclusions

Fossiliferous Limestone

Biogenic Sedimentary Rock containing invertebrate fossils

Likely limestone

Calcite-rich carbonate rock, principally calcium carbonate (CaCO₃)

Shale

Laminated Mudstone

Quartz-rich rock fragment

Likely iron-stained milky quartz, predominantly silicon dioxide (SiO₂); precise rock identification is uncertain from the image

Weathered gray rock fragment

Tentatively shale or fine-grained sandstone; exact identification requires testing