Mineral, Possibly Rock Fragment Containing A Mineral

Tumbled quartz-rich stone, possibly granite or sandstone

Uncertain from image; likely quartz (SiO₂) with iron-oxide and feldspar impurities

Sandstone

Arenite (Clastic Sedimentary Rock)

Granite fragment

Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz, feldspar, and mica

Quartz-rich rock, possibly granite or pegmatite fragment

Likely quartz–feldspar aggregate; exact identification is uncertain from the photograph

Small quartz-rich pebble, possibly milky quartz

Quartz (silicon dioxide, SiO₂)

Sandstone (Calcareous)

Clastic sedimentary rock (primarily SiO2 with CaCO3 cement)

Red Sandstone

Arenite (primarily Quartz with Hematite cement)

Sandstone (with Limonite staining)

Arenite (primarily SiO2 with FeO(OH)·nH2O)

Light-colored weathered stone, possibly limestone or quartz-rich rock

Indeterminate; likely calcitic limestone (mostly CaCO₃) or quartz sandstone (SiO₂)

Likely weathered quartz-rich rock fragment

Uncertain; possibly quartz sandstone or a pale feldspathic rock

Note regarding baguette production (not a rock)

Digital text image - Somali language

Likely raw mica-bearing mineral fragment

Possibly biotite mica or a biotite-rich metamorphic fragment; identification is limited by the dark, blurred image

Brecciated rock, likely polymict breccia

Polymict breccia; exact lithology cannot be determined from the image

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

Laterite/limonite-rich material; commonly dominated by goethite (FeO(OH)) and hydrated iron oxides

Weathered limestone or calcareous rock

Calcite-rich limestone (predominantly CaCO₃), possibly fossiliferous

Dark gray, fine-grained rock fragment (possibly basalt)

Basalt (tentative identification; image alone cannot confirm)

Likely galena-bearing ore fragment

Galena (PbS), possibly with oxidized sulfides or host rock

Dark gray crystalline rock, possibly mica-rich schist or graphite-bearing gneiss

Indeterminate; likely quartz–feldspar–mica metamorphic rock

Brecciated jasper (iron-rich jasper)

Cryptocrystalline silica, mainly microcrystalline quartz (SiO₂), with iron-oxide minerals such as hematite and goethite

Weathered limestone fragment

Limestone, predominantly calcite (CaCO₃), possibly fossiliferous or dolomitic

Sandstone (Quartzose)

Arenite (primarily SiO2)

Tiny metallic-looking mineral or rock fragment

Unidentifiable from the image; possibly a small metallic mineral grain

Small tan rock fragment

Unidentifiable lithic fragment; mineral composition undetermined

Weathered quartz-rich rock, likely milky quartz/quartzite

Quartz (SiO₂); possibly quartzite if metamorphosed sandstone

Quartz-bearing granite or pegmatite fragment

Likely granitic material composed mainly of quartz (SiO₂), feldspar, and possibly biotite or hornblende

Sandstone

Arenite (SiO2 based)

Fossiliferous Rock (Invertebrate Fossil in Matrix)

Fossiliferous limestone or shaly matrix containing skeletal fossil remains

Likely green aventurine or serpentine-bearing stone

Indeterminate from image; possibly quartzite with fuchsite mica or serpentinized ultramafic rock

Fossiliferous Sandstone / Fossil Fragment

Fossiliferous Sedimentary Matrix with Indeterminate Fossil Material

Likely iron-stained quartz or ironstone with a glittering mica-like surface

Uncertain from the photo; possibly quartz (SiO₂) with iron-oxide staining and mica or sulfide grains

Red Sandstone

Arenite (with iron oxide cement)

Quartz-rich pebble, possibly vein quartz

Quartz (SiO₂), possibly with iron-oxide staining and minor inclusions

Likely weathered quartz-bearing rock fragment

Indeterminate; possibly granitic or metamorphic quartz–feldspar aggregate

Likely fossiliferous limestone fragment

Calcite-rich limestone, possibly containing fossil or shell fragments (primarily CaCO₃)

Small quartz-rich rock fragment (tentative)

Quartz, silicon dioxide (SiO₂), possibly in a feldspar-bearing granite fragment

Iron-rich rock fragment, possibly weathered hematite-bearing basalt

Likely basalt with iron oxides/hydroxides; composition may include hematite (Fe₂O₃) or goethite (FeO(OH))

Sandstone (likely Greywacke variant)

Arenite

Sandstone

Arenite

Rounded sandstone pebble

Quartz-rich sandstone, possibly iron-stained litharenite

Tumbled fossiliferous limestone

Calcite-rich limestone (CaCO₃), possibly containing fossil fragments

Quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂), possibly quartzite (recrystallized quartz sandstone)

Quartz-rich rock, possibly milky quartz or quartzite fragment

Quartz (SiO₂), potentially quartzite if metamorphic