Mineral With Artificial Coating

Quartz Pebble with Iron Staining

Silicon Dioxide (SiO2) with Hematite/Limonite matrix

Amethyst cluster

Quartz, SiO₂, violet variety (amethyst)

Polished malachite cabochon

Malachite, Cu₂CO₃(OH)₂

Dyed Purple Agate Sliced Tablet

Silicon Dioxide (SiO2), variety Chalcedony

Peacock Ore

Bornite (Cu5FeS4)

Red Sandstone

Sedimentary Clastic Rock (Quartz Arenite / Arkose)

Small brown rock fragment, likely sandstone

Quartz-rich sandstone (tentative identification)

Polished black-and-gold mineral fragment, likely chalcopyrite

Chalcopyrite (CuFeS₂), possibly tarnished or coated

Unknown metallic sulfide-bearing rock, possibly chalcopyrite or bornite

Tentative: chalcopyrite (CuFeS₂) or bornite (Cu₅FeS₄)

Orange chalcedony or weathered quartz pebble

Microcrystalline quartz, SiO₂; possibly iron-oxide-stained chalcedony

Vanadinite

Vanadinite, Pb₅(VO₄)₃Cl

Sandstone (Red / Iron-stained)

Sandstone (composed predominantly of SiO2 with Fe2O3 cement)

Red Sandstone

Clastic Sedimentary Rock (typically contains Quartz and Iron Oxide)

Tumbled orange calcite

Calcite (CaCO₃)

Concrete-embedded rock fragment, likely weathered granite or gneiss

Probable granitic silicate assemblage: quartz, feldspar, and dark mica/amphibole

Reddish sandstone (probable)

Quartz-rich sandstone; exact composition cannot be confirmed from the image

Pink Dyed Agate

Silicon Dioxide (SiO2) - Variety Agate

Rose Quartz

Silicon Dioxide (SiO2) with traces of titanium, iron, or manganese

Quartz with Iron Staining

Silicon Dioxide (SiO2)

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

Sandstone with Desert Varnish

Arenite (SiO2 predominantly) with Ferromanganese coating

Granite

Granite (Plutonic Igneous Rock)

Druzy Quartz on Milky Quartz

Silicon Dioxide (SiO2)

Quartz crystal fragment in weathered host rock

Quartz (SiO₂), possibly in a feldspathic or iron-stained matrix

Tumbled quartz pebble

Quartz, silicon dioxide (SiO₂), likely milky quartz

Possible tumbled jasper or iron-rich chert

Microcrystalline quartz (SiO₂), commonly colored by iron oxides

Weathered vesicular basalt (likely amygdaloidal basalt)

Basalt, chiefly plagioclase + pyroxene ± olivine; cavities may contain secondary zeolites, calcite, or chlorite

Quartz geode

Microcrystalline quartz (chalcedony) shell lined with drusy quartz, SiO₂

Quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂), possibly in a quartzite or hydrothermal vein matrix

Iron-rich sulfide-bearing rock, likely pyrite-rich shale or limonite-goethite specimen

Likely pyrite (FeS₂) with oxidation products goethite/limonite (FeO(OH)·nH₂O), possibly in shale or quartz matrix

Ferruginous Quartz

Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)

Unakite (likely)

Epidote–K-feldspar–quartz aggregate; commonly derived from altered granite

Ammonite fossil in matrix

Fossilized ammonoid cephalopod; likely an ammonite such as Dactylioceras or a related Jurassic taxon

Iron-rich basalt or weathered ironstone

Basalt, likely variolitic/vesicular and coated with iron oxides; composition mainly plagioclase, pyroxene, and magnetite/hematite

Kaolinite (Chalky Clay)

Kaolinite (Al2Si2O5(OH)4)

Chalcedony breccia (possibly agate with drusy quartz)

Microcrystalline quartz, SiO₂, with crystalline quartz and dark matrix/inclusions

Likely labradorite-bearing rocks

Labradorite, a plagioclase feldspar (approximately NaAlSi₃O₈–CaAl₂Si₂O₈), possibly in mafic host rock

Botryoidal chalcedony (possibly common opal)

Microcrystalline quartz, SiO₂; pale portions may include hydrated silica opal, SiO₂·nH₂O

Tumbled quartz pebble

Quartz (SiO₂), likely milky or iron-stained quartz

Botryoidal hemimorphite on matrix

Hemimorphite, Zn₄Si₂O₇(OH)₂·H₂O, likely with associated quartz or calcite

Likely tumbled quartz-rich pebble

Quartz (SiO₂), possibly a weathered quartzite or chalcedony pebble

Quartz cluster, possibly druzy quartz on matrix

Quartz (SiO₂), likely microcrystalline to coarse crystalline; associated matrix uncertain