Mineral (Native Element Alloy)

Iron-rich weathered rock, possibly limonite/goethite-bearing ore

Limonite (hydrated iron oxides; chiefly goethite, FeO(OH), with hematite and other oxides possible)

Weathered quartz-rich rock, likely granite or pegmatite

Granitic pegmatite; chiefly quartz (SiO₂), feldspar, and mica, with possible iron-oxide staining

Pyrite-bearing quartz rock

Pyrite (FeS₂) in quartz-rich matrix, possibly with mica or chlorite

Agate Geode / Thunderegg

Chalcedony (cryptocrystalline variety of Quartz), SiO2

Polished black granite with golden sulfide veining

Likely gabbro or black granite containing pyrite/chalcopyrite; exact identification requires testing

Fossilized bone fragment, possibly vertebrate tooth or jaw

Mineralized vertebrate bone; commonly apatite [Ca5(PO4)3(F,OH,Cl)] replacing original bone

Gold-bearing quartz vein rock

Quartz (SiO₂) with probable native gold and iron-oxide/sulfide minerals

Turquoise with Pyrite

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O] with Iron Pyrite (FeS2)

Pyrite-bearing rock, likely quartz vein

Pyrite (FeS₂) in quartz-rich host rock

Chrysocolla Cuprite

Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) and Cu2O (Cuprite)

Red Jasper

Jasper (Silicon Dioxide, SiO2 with iron oxide impurities)

Galena-bearing sulfide ore

Galena (lead sulfide, PbS), possibly with sphalerite and/or pyrite

Blue cabochon ring stone, likely lapis lazuli or blue chalcedony

Uncertain from image; possible lazurite-bearing lapis lazuli (Na₃Ca(Si₃Al₃)O₁₂S) or cryptocrystalline quartz (SiO₂)

Likely weathered basalt with iron-oxide alteration

Basalt (fine-grained mafic volcanic rock), chiefly plagioclase and pyroxene with altered iron-bearing minerals

Weathered basalt (possibly iron-stained volcanic rock)

Basalt; primarily plagioclase feldspar and pyroxene, commonly with olivine and iron oxides

Native gold specimen (probable gold-bearing quartz)

Native gold, Au, with likely quartz (SiO₂) and possibly iron-oxide/sulfide matrix

Ferrochrome Slag

Industrial Glassy Slag (Fe-Cr alloy byproduct)

Weathered quartz-bearing rock, possibly iron-stained quartzite or granitic pegmatite

Indeterminate; likely quartz-rich silicate rock with iron-oxide staining (SiO₂-dominant)

Weathered iron-rich rock, possibly limonite-bearing quartzite or altered basalt

Indeterminate; likely quartz (SiO₂) with iron oxides/hydroxides such as limonite/goethite

Quartz-rich gold-brown mineral specimen, possibly iron-stained quartz

Quartz (SiO₂), likely with limonite/goethite staining and minor sulfide or mica inclusions

Red Jasper

Silicon Dioxide (SiO2) with impure Iron oxides

Red Jasper

Jasper (Silicon Dioxide with iron oxide inclusions), SiO2

Turquoise

CuAl6(PO4)4(OH)8·4H2O (Hydrous Phosphate of Copper and Aluminum)

Iron-stained quartz-rich rock, possibly gold-bearing quartz

Quartz (SiO₂) with iron-oxide staining; possible limonite/goethite matrix

Thunderegg (Agetized Geode nodule)

Rhyolitic Agate Nodule (SiO2 filling volcanic cavities)

Chert (variations include Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Turquoise

Hydrous phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O

Argillite

Argillite (Fine-grained sedimentary rock composed mostly of clay-sized particles)

Vesicular Basalt (Scoria)

Basalt (Vesicular texture)

Chert (Flint nodules in limestone)

Silicon Dioxide (SiO2)

Native gold-bearing sulfide specimen

Native gold (Au), likely intergrown with pyrite (FeS₂) or chalcopyrite (CuFeS₂)

Red Jasper

Silicon Dioxide with Iron Oxide (SiO2)

Weathered iron-rich rock, possibly limonite-bearing quartzite or ironstone

Limonite/goethite-rich Fe-oxide rock; exact identification requires testing

Sandstone (Nut-stone / Cup-stone artifact)

Quartz Arenite / Worked Sedimentary Rock

Amygdaloidal Basalt

Amygdaloidal Basalt (extrusive volcanic rock)

Likely raw galena fragment

Galena (lead sulfide, PbS), possibly with metallic sulfide matrix

Moqui Marble (Iron Oxide Concretion)

Iron Oxide Concretion (primarily Limonite/Hematite around a Sandstone center)

Pyrite-bearing quartz vein rock

Pyrite (FeS₂) with quartz (SiO₂), likely in a schistose or altered host rock

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Turquoise in Matrix

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide impurities