Sedimentary Or Igneous (Secondary Formation)

Limonite and Goethite (Ironstone)

Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)

Polished malachite

Malachite, Cu₂CO₃(OH)₂

Orange Calcite

Calcium Carbonate (CaCO3)

Agate Geode

Chalcedony (SiO2 - Silicon Dioxide)

Likely foliated metamorphic rock (quartz-mica schist or gneiss)

Quartz–feldspar–mica metamorphic rock; exact identification requires a fresh surface and tests

Garnet-bearing metamorphic rock, likely garnet schist or amphibolite

Almandine garnet (Fe₃Al₂Si₃O₁₂) in mica- or amphibole-rich matrix

Pyrite

Iron Pyrite (FeS₂)

Weathered vesicular volcanic rock, likely basaltic scoria

Vesicular basalt/scoria; chiefly plagioclase, pyroxene, olivine, and volcanic glass

Rounded river pebble, likely basaltic or andesitic rock

Fine-grained mafic to intermediate volcanic rock; exact identification requires testing

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Weathered, vesicular volcanic rock (likely basaltic scoria)

Scoria, probably basaltic; exact identification requires testing

Unidentified orange-brown rock fragment

Likely weathered iron-rich volcanic rock or ochre-bearing material; exact identification is impossible from the blurred image

Granite (weathered/river-tumbled)

Granite (Plutonic Igneous Rock)

River Pebble (Gneiss / Granitic Schist)

Metamorphic Rock (Quartz-Feldspar-Mica assembly)

Quartz

Silicon Dioxide (SiO2)

Rounded granitic cobble (granite)

Granite; chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende

Chert (Limestone-based)

Silicon Dioxide (SiO2)

Pyrite

Pyrite (FeS₂)

Likely raw mica-bearing metamorphic rock or mineral fragment

Tentatively biotite schist; visually similar dark mica-rich material

Hematite (likely Botryoidal or Specularite variant)

Iron(III) oxide (Fe2O3)

Banded Agate (Dyed / Polished)

Microcrystalline Quartz (SiO2)

Magnetite

Magnetite (Fe3O4)

Clear Quartz

Silicon Dioxide (SiO2)

Olivine Basalt (with Epidote and Serpentine)

Mafic Volcanic Rock (Basalt)

Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 secondary)

Botryoidal Chalcedony (Agate/Carnelian)

Chalcedony (SiO2)

Chert (Flint / Jasper)

Silicon Dioxide (SiO2)

Desert rose

Gypsum (selenite) rosette, CaSO₄·2H₂O

Biotite-bearing gneiss or schist

Quartz–feldspar–mica metamorphic rock, likely mica schist/gneiss

Prehnite

Prehnite, Ca2Al(AlSi3O10)(OH)2

Weathered quartz-bearing metamorphic rock

Likely quartz–feldspar schist or gneiss, possibly with iron-oxide alteration

Yellow-brown chert or jasper

Microcrystalline quartz (SiO₂), likely iron-oxide-bearing chert/jasper

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)

Orange Calcite

Calcium Carbonate (CaCO3)

Fossiliferous limestone

Bioclastic limestone, commonly crinoidal or shelly limestone (calcite, CaCO₃)

Raw garnet-rich metamorphic rock

Likely garnet-bearing schist or garnetite; garnet-group silicates, commonly almandine (Fe₃Al₂Si₃O₁₂)

Magnetite or Hematite Nodule

Iron Oxide (Fe3O4 or Fe2O3)

Carnelian

Silicon Dioxide (SiO2) - variety of Chalcedony

Fossiliferous limestone, likely coral or shell-rich fragment

Calcite (CaCO₃), commonly bioclastic limestone containing fossilized marine organisms

Native Copper (in coinage alloy)

Copper (Cu)