Mineral, Possibly Rock Fragment Containing A Mineral

Yellow-orange tumbled stone, likely carnelian or orange jasper

Cryptocrystalline quartz (chalcedony), SiO₂; possibly iron-rich jasper

Sandstone

Arenite (predominantly SiO2)

Sandstone (likely Quartzose Sandstone)

Arenite (composed primarily of SiO2)

Fossiliferous shale or slate with plant impressions

Carbonaceous mudstone/shale; possible fossil plant material (often fern-like impressions)

Likely silver-gray granite or granitic gneiss fragment

Granite; primarily quartz (SiO₂), feldspar, and mica (exact identification uncertain from image)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 based)

Sandstone (with Iron Staining)

Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 oxides)

Sandstone

Arenite (SiO2 principal)

Conglomerate

Conglomerate (a clastic sedimentary rock)

Yellow chalcedony (possibly jasper/chalcedony)

Microcrystalline quartz, SiO₂; yellow coloration likely from iron oxides/hydroxides

Weathered quartz-rich rock, possibly sandstone or milky quartz

Primarily quartz (silicon dioxide, SiO₂); exact identification is uncertain from the photograph

Unidentified pink-and-green mineral-bearing rock

Not reliably identifiable from the image; possible pink feldspar with green epidote or another green mineral

Quartz-rich rock, likely milky quartz with iron-oxide staining

Quartz (SiO₂), possibly quartzite or a quartz vein fragment

Likely iron-rich rock or weathered metallic mineral fragment

Uncertain; possibly limonite/goethite or iron-bearing slag

Small dark rock fragment

Indeterminate; possibly basalt or scoria

Iron-rich sandstone or laterite fragment

Ferruginous sandstone; possibly laterite/goethite-rich ironstone

Mixed rounded rock and mineral gravel

Predominantly weathered basalt, quartz-rich fragments, and iron-stained silicate rocks; exact species cannot be determined reliably from the image

Granite

Plutonic Igneous Rock

Ironstone (likely siderite or goethite-rich siltstone)

Ferruginous Siltstone

Fossiliferous Sandstone / Mudstone

Sedimentary Rock (Clastic with Fossiliferous Inclusions)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Sandstone (Quartzose Sandstone)

Arenite (primarily SiO2)

Weathered light-colored stone, likely limestone

Calcitic limestone; predominantly calcium carbonate (CaCO₃), possibly chalky or dolomitic

Milky quartz-rich rock, possibly quartzite

Quartz (SiO₂), likely in a quartzite or quartz-vein matrix

Tumbled jasper pebble (likely ocean jasper or brecciated jasper)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide and other mineral inclusions

Likely quartz-bearing rock or quartz crystal fragment

Quartz, silicon dioxide (SiO₂), possibly with iron-stained matrix

Sandstone (Graywacke type)

Clastic Sedimentary Rock (Lithic Sandstone)

Weathered dark igneous rock fragment

Likely basalt or andesite; exact identification is uncertain from the photograph

Granite Pebble

Intrusive Igneous Rock

Polished agate or chalcedony slice (uncertain)

Microcrystalline quartz, SiO₂; possibly fossil-bearing chalcedony

Weathered iron-rich stone, possibly limonite-bearing rock

Limonite/goethite-rich material; composition commonly approximated as hydrated iron oxides, FeO(OH)·nH₂O

Coprolite

Fossilized Feces

Weathered iron-rich rock fragment

Uncertain; possibly limonite/goethite-bearing ironstone or weathered basalt

Rounded quartz-rich pebble

Likely microcrystalline quartz (chalcedony), possibly a weathered quartz or feldspar pebble

Purple quartz-bearing pebble, possibly amethyst or lepidolite

Likely quartz (SiO₂) with iron-related purple coloration; exact identification requires testing

Dark volcanic rock, likely basalt

Basalt; fine-grained mafic silicate rock dominated by plagioclase and pyroxene, commonly with olivine

Sandstone (Siltstone or Fine-grained)

Clastic sedimentary rock (primarily SiO2)

Amethyst-bearing quartz geode fragment

Quartz, SiO₂; purple coloration from trace iron and irradiation

Basalt Porphyry

Porphyritic Basalt

Sandstone (with Lichen)

Arenite (primarily SiO2)

Generic Rock Fragment

Rock Fragment