Sedimentary Rock (Possibly Composed Of Various Minerals)

Siltstone

Siltstone (primarily composed of SiO2 with various clay minerals)

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)

Unidentified coarse-grained rock fragment, possibly granite

Possible granite: quartz, feldspar, and dark mica or amphibole; identification is uncertain from the image

Limonite Concretion

Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)

Gem Gravel

Alluvial Gem Gravel (Mixed silicate minerals)

Coarse Sandstone

Arenite (SiO2 based)

Mica Schist

Metamorphic rock primarily composed of quartz, micas, and feldspar

Sandstone

Arenite

Mica-rich schist

Mica schist, composed chiefly of muscovite and/or biotite mica with quartz and possibly feldspar

Sandstone

Arenite (SiO2 with various cementation agents)

Weathered vesicular volcanic rock, likely pumiceous andesite or rhyolite

Pumiceous intermediate-to-felsic volcanic rock; commonly composed of plagioclase, quartz, alkali feldspar, and volcanic glass, with possible iron-oxide staining

Granodiorite

Phaneritic intrusive igneous rock (intermediate composition)

Dark fine-grained rock fragment

Likely basalt or basaltic scoria; exact identification requires testing

Sandstone

Quartz Arenite (a type of sandstone composed of more than 90% quartz)

Weathered iron-rich rock, likely laterite or ironstone

Ferruginous laterite/ironstone, composed mainly of goethite (FeO(OH)), hematite (Fe₂O₃), and clay minerals

Tumbled quartz or pale agate pebble

Quartz (SiO₂), possibly microcrystalline chalcedony

Greenstone / Greenschist

Greenschist facies metamorphic rock (composed primarily of chlorite, actinolite, and epidote)

Sandstone

Arenite (SiO2 primarily)

Pebble (likely Sandstone or Granitic Pebble)

Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)

Tumbled dark gray stone, possibly basalt or andesite

Fine-grained mafic to intermediate volcanic rock; exact mineralogy cannot be confirmed from the photograph

Shale (possibly)

Shale (fine-grained clastic sedimentary rock)

Sandstone Pebble

Sedimentary Clastic Rock (Quartz Arenite)

Biotite-bearing granite

Granite, composed mainly of quartz (SiO₂), potassium feldspar, plagioclase, and biotite mica

Weathered iron-stained quartzite or sandstone cobble

Quartzite (quartz-rich rock), possibly ferruginous sandstone

Mixed Quartz and Mineral Gravel

Silicon Dioxide (SiO2) and assorted silicate minerals

Red Sandstone

Arenite (primarily Quartz with Hematite cement)

Metal Chain (Likely Steel or a Steel Alloy)

Steel (primarily iron and carbon); specific alloy unknown

Limestone

Sedimentary rock composed primarily of Calcium Carbonate (CaCO3)

Pebble or Cobble (likely composed of sandstone or conglomerate)

Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)

Quartz-rich sandstone (possibly arkosic sandstone)

Clastic sandstone composed mainly of quartz (SiO₂), with feldspar and mica fragments cemented by silica or carbonate

Granite

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

Bauxite

Bauxite (Mixture of Hydrous Aluminum Oxides)

Granite

Phaneritic Felsic Igneous Rock

Banded river pebble, likely gneiss

Foliated quartz–feldspar rock, possibly banded gneiss

Likely sodalite (rough blue specimen)

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂

Quartz pebble

Silicon Dioxide (SiO2)

Polished granite pebble

Granite, a quartz–feldspar plutonic rock

Granite

Intrusive Igneous Rock (composed primarily of quartz, alkali feldspar, and plagioclase)

Small blue-green mineral or stone bead

Unidentified opaque blue-green mineral; the image is insufficient for reliable species identification

Red Sandstone

Arenite (primarily SiO2 with Fe2O3)

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)

Seashell (Calcium Carbonate)

Calcium Carbonate (CaCO3)