Mineral With Artificial Coating

Quartz geode/drusy quartz

Quartz, silicon dioxide (SiO₂), likely chalcedony-lined geode

Titanium Aura Quartz

Silicon Dioxide (SiO2) coated with Titanium and Niobium

Quartz with Limonite Staining

Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)

Tumbled smoky quartz

Quartz, silicon dioxide (SiO₂), smoky variety colored by irradiation-related defects

Tumbled smoky quartz

Quartz (SiO₂), smoky variety

Peacock ore (bornite/chalcopyrite specimen)

Bornite, Cu₅FeS₄, commonly with chalcopyrite (CuFeS₂)

Dyed Agate Slice

Silicon Dioxide (SiO2)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Ferruginous Quartz (Iron-stained Quartz)

Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)

Quartz with Iron Staining

Silicon Dioxide (SiO2) with Hematite inclusions

Sandstone (Ferruginous)

Arenite with Iron Oxide staining (Fe2O3)

Sandstone (Red / Iron-stained)

Sandstone (composed predominantly of SiO2 with Fe2O3 cement)

Red Sandstone

Clastic Sedimentary Rock (typically contains Quartz and Iron Oxide)

Red Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3)

Polished malachite cabochon

Malachite, Cu₂CO₃(OH)₂

Rainbow Quartz (Fire and Ice Quartz)

Silicon Dioxide (SiO2)

Clear Quartz Cluster

Silicon Dioxide (SiO2)

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)

Blue Dyed Agate

Cryptocrystalline Quartz (SiO2)

Pink Dyed Agate (Pink Agate Slice)

Silicon Dioxide (SiO2) - Chalcedony / Cryptocrystalline Quartz

Dyed Pink Agate (Crackled)

Silicon Dioxide (SiO2) - Chalcedony variety

Chrysocolla

Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O

Botryoidal quartz (likely chalcedony/agate)

Microcrystalline silica, SiO₂; possibly quartz-rich chalcedony with iron-oxide staining

Blue Dyed Quartzite

Silicon Dioxide (SiO2) with artificial pigment

Likely rose quartz and milky quartz specimens

Quartz, silicon dioxide (SiO₂)

Botryoidal pyrite (likely with quartz or chlorite matrix)

Pyrite, FeS₂; botryoidal aggregate

Likely quartz crystal cluster

Quartz (silicon dioxide, SiO₂)

Fossilized bivalve shell fragment

Fossil Mollusca, likely a bivalve (class Bivalvia); exact genus cannot be determined from the image

Weathered iron-rich basalt or volcanic rock

Fine-grained mafic rock, likely basalt with iron-oxide weathering (hematite/goethite)

White quartz cluster

Quartz (silicon dioxide, SiO₂), likely a drusy or microcrystalline cluster

Quartz Pebble with Iron Staining

Silicon Dioxide (SiO2) with Hematite/Limonite matrix

Amethyst cluster

Quartz, SiO₂, violet variety (amethyst)

Quartz fragment (likely milky quartz)

Quartz, silicon dioxide (SiO₂)

Titanium Amethyst Geode

Silicon Dioxide (SiO2) with Titanium/Metal Vapor Deposition Layer

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)

Sandstone

Arenite (SiO2 based)

Quartz with Iron Staining

Silicon Dioxide (SiO2)

Druzy Quartz on Milky Quartz

Silicon Dioxide (SiO2)

Likely weathered sandstone or iron-rich sedimentary rock

Quartz-rich sandstone, possibly ferruginous sandstone

Weathered basalt or volcanic scoria fragment

Basaltic volcanic rock; chiefly plagioclase, pyroxene, and iron-rich oxides

Sandstone (Iron-stained)

Sandstone (rich in Quartz and Hematite/Limonite coatings)