Industrial By Product

Galena-bearing sulfide ore

Galena (PbS), likely with sphalerite, pyrite, and/or iron-oxide matrix

Weathered quartz-rich granite

Granite, primarily quartz (SiO₂), feldspar, and minor biotite/mica or iron oxides

Weathered, iron-stained metamorphic rock (probable schist or gneiss)

Quartz–feldspar–mica metamorphic rock; exact identification requires a fresh surface and thin-section or mineral tests

Clay (as a rock-forming material)

Clay minerals (e.g., Kaolinite group, Smectite group, Illite group, Chlorite group)

Mixed gravelly conglomeratic road aggregate

Polymictic clast-supported conglomerate or fill; composition varies, commonly quartz, feldspar, basalt, and weathered rock fragments

Chert / Flint

Cryptocrystalline quartz (SiO2)

Honey calcite

Calcite (calcium carbonate, CaCO₃)

Serpentinized ultramafic rock with chromite

Serpentinite; chiefly serpentine-group minerals, Mg-rich silicates, with probable chromite and minor magnetite

Serpentine-rich metamorphic rock

Serpentinite; chiefly antigorite/lizardite/chrysotile, commonly with magnetite and carbonate

Small marine shell fragment

Calcareous shell, primarily calcium carbonate (aragonite or calcite); exact taxon indeterminate

Hematite pseudomorph after a fossil or mineralized object (likely iron-oxide concretion)

Hematite, Fe₂O₃, possibly limonite/goethite-bearing

Vesicular basalt

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase, pyroxene, and commonly olivine

Likely serpentine or serpentine-rich stone

Serpentine-group minerals, chiefly antigorite/lizardite; approximate formula Mg₃Si₂O₅(OH)₄

Likely raw galena-bearing ore

Galena (PbS), possibly associated with dark sphalerite or matrix minerals

Iron-rich quartzite or ferruginous metamorphic rock

Ferruginous quartzite, likely hematite/goethite-bearing quartzite; SiO₂ with Fe₂O₃/FeO(OH)

Green aventurine or chrysoprase rough

Quartzite with fuchsite mica (aventurine) or chalcedony colored by nickel (chrysoprase)

Pebble (likely Quartzite or Chert)

Clastic Sediment, potentially composed of SiO₂ (Quartz)

Chert

Microcrystalline quartz (SiO2)

Botryoidal hematite-goethite ironstone

Hematite (Fe₂O₃) with goethite (FeO(OH)), likely iron-rich weathering product

Galena (likely)

Galena, lead sulfide (PbS)

Iridescent bismuth crystal

Bismuth (Bi), artificially crystallized and likely oxidized/coated

Serpentinite

Serpentinite; chiefly serpentine-group minerals (lizardite, chrysotile, antigorite), with magnetite and relic mafic minerals

Calcite crystal

Calcite (CaCO₃)

Weathered volcanic tuff or breccia

Lithified volcanic ash and rock fragments; likely rhyolitic to andesitic tuff/breccia

Bornite (“peacock ore”), likely weathered copper sulfide

Bornite, Cu₅FeS₄; possibly chalcopyrite, CuFeS₂, with iridescent tarnish

Chrysocolla-bearing copper ore

Chrysocolla (hydrated copper aluminum silicate), commonly mixed with malachite, quartz, and iron oxides

Tumbled serpentine-rich rock

Serpentinite, likely antigorite/lizardite with magnetite and minor carbonates

Milky quartz specimen

Quartz (silicon dioxide, SiO₂), likely massive milky quartz with possible iron-oxide staining and minor feldspar or mica

Pearl-bearing oyster shell

Nacreous shell, primarily aragonite (CaCO₃), with natural pearls (calcium-carbonate nacre)

Quartz

Silicon Dioxide (SiO₂)

Chert (Black Chert/Flint)

Silicon Dioxide (SiO2)

Iron-rich meteorite (probable stony-iron or weathered iron meteorite)

Unclassified meteorite; possible ordinary chondrite with iron-nickel metal and weathering products

Beaded gemstone bracelet, likely amethyst and mixed polished stones

Amethyst: quartz (SiO₂); other beads appear to be assorted quartz/chalcedony or jasper

Slag (Industrial Glassy Byproduct)

Anthropogenic silicate byproduct (Slag)

Cobalt Glass Slug (Man-made Glass)

Amorphous Silica with Cobalt Oxide (SiO2 + CoO)

Diamond (or Diamond Simulant)

C (Carbon) or synthetic equivalent

Hematite

Hematite (Fe2O3)

Pyrite nodule (probable iron sulfide concretion)

Pyrite, FeS₂, likely weathered within a sedimentary concretion

N/A - Image does not contain a rock or mineral

Anthropogenic textile material

Weathered quartz-rich rock, likely quartzite

Quartzite; predominantly crystalline SiO₂ with minor iron-oxide staining

Iron Slag

Iron/Steel Slag (Ferrosilicate Glass)

Aventurine

Quartz (Aventurine variety)