Sedimentary Or Igneous Fragment

Unidentified polished stone fragments

Indeterminate; likely mixed lapidary specimens, possibly jasper, agate, or quartz-bearing rock

Foliated metamorphic rock, likely schist

Mica schist (likely quartz–mica schist; exact identification requires closer examination)

Biotite-rich schist (likely mica schist)

Mica schist; predominantly quartz, biotite mica, and feldspar

Dark gray rock fragment, likely basalt

Basalt; chiefly plagioclase feldspar and pyroxene, commonly with minor olivine and magnetite

Weathered quartz-rich metamorphic rock, likely gneiss or schist

Quartz–feldspar–mica gneiss/schist (tentative; image resolution limits certainty)

Weathered granite fragment

Granite, a quartz–feldspar–mica intrusive rock

Small gray translucent stone, possibly quartz or glassy mineral

Uncertain; likely microcrystalline quartz (SiO₂), but the image is insufficient for definitive identification

Likely quartz fragment

Quartz (silicon dioxide, SiO₂)

Likely garnet-bearing schist or gneiss

Mica schist/gneiss containing quartz, feldspar, mica, and probable almandine garnet

Quartz

Silicon Dioxide (SiO2)

Iron-stained quartz-rich rock (possibly ironstone or ochre-coated quartz)

Undetermined ferruginous rock; yellow-brown coloration likely from goethite and/or limonite (hydrated iron oxides)

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Arkosic Sandstone (or Conglomeritic Sandstone fragment)

Arkose (rich in feldspar)

Asphalt aggregate

Human-made bituminous asphalt containing crushed silicate rock aggregate

Biotite mica schist (probable)

Schist dominated by biotite mica; commonly quartz–feldspar–biotite

Iron-stained quartz-bearing rock, possibly weathered granite or gneiss

Quartz–feldspar rock with iron-oxide staining; exact identification requires testing

Likely quartz-rich gravel fragment (uncertain identification)

Quartz, silicon dioxide (SiO₂), possibly mixed with feldspar or other light-colored minerals

Weathered quartz-rich pebble (tentative)

Likely quartz/chalcedony, SiO₂, possibly iron-stained

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Green Aventurine

Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2

Quartz-rich rock, possibly milky quartz or quartzite fragment

Quartz (SiO₂), potentially quartzite if metamorphic

Geode with Quartz Crystals

SiO2 (Silicon Dioxide) in a geode formation

Mica-rich schist (probable)

Mica schist, composed mainly of mica minerals with quartz and possibly feldspar

Mica-rich schist

Muscovite–quartz schist (tentative; image alone cannot confirm mineral composition)

Biotite-rich schist (mica schist)

Mica schist, chiefly biotite (K(Mg,Fe)₃AlSi₃O₁₀(OH,F)₂), with possible quartz and feldspar

Weathered schist or gneiss

Quartz–feldspar–mica metamorphic rock

Gneiss

Gneissic Metamorphic Rock

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Black tourmaline (schorl), probable

Schorl tourmaline, NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Coarse Sand Grain / Lithic Fragment

Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)

Weathered schist or gneiss cobble

Foliated silicate rock, likely mica schist or biotite gneiss

Quartz-rich rock fragment

Milky quartz, primarily silicon dioxide (SiO₂), possibly quartzite or a feldspar-bearing vein rock

Clear quartz fragment

Quartz (silicon dioxide, SiO₂)

Small white crystalline mineral fragment

Indeterminate; possibly calcite or quartz

Likely tumbled quartz or calcite

Quartz (SiO₂) or calcite (CaCO₃); exact identification requires hardness and acid tests

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Quartz

Silicon Dioxide (SiO2)

Mixed rock and mineral collection

Assorted geological specimens; individual species cannot be reliably identified from the image

Weathered quartz-mica schist

Quartz–muscovite/biotite schist, locally iron-oxide stained

Quartz pebble

Silicon dioxide (SiO2)

Red Garnet (likely Almandine or Pyrope)

Garnet group: X3Y2(SiO4)3 (e.g., Almandine: Fe3Al2Si3O12)

Likely weathered quartz-rich rock, possibly smoky quartz or chert

Quartz (SiO₂), though exact identification is uncertain from the photograph