Mineral With Artificial Coating

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Polished malachite specimen

Malachite, Cu₂CO₃(OH)₂

Polished malachite

Malachite, Cu₂CO₃(OH)₂

Red Sandstone

Arenite with Hematite (Fe2O3)

Tiger's Eye

Silicon dioxide with crocidolite inclusions (SiO2)

Likely polished slate

Slate, a fine-grained metamorphic rock composed mainly of quartz, mica, and chlorite

Weathered metallic sulfide-bearing rock, possibly pyrite-rich ore

Tentatively pyrite (FeS₂) with iron oxides and host rock; exact identification requires testing

Quartz Pebble (Iron-Stained)

Silicon Dioxide (SiO2)

Clear Quartz Cluster

Silicon Dioxide (SiO2)

Dyed Blue Agate Slice

Silicon Dioxide (SiO2)

Blue Banded Agate (Dyed)

Silicon Dioxide (SiO2) - variety of Chalcedony

Dyed Blue Agate

Cryptocrystalline Quartz (SiO2)

Likely iron-rich sandstone or ironstone

Ferruginous sandstone/ironstone; exact identification is uncertain from the photograph

Tumbled dark stone, possibly river pebble or hematite

Uncertain; candidates include hematite (Fe₂O₃), basalt, or dark chert

Rainbow Quartz (Fire and Ice Quartz)

Silicon Dioxide (SiO2)

Amethyst druzy cluster

Amethyst, purple variety of quartz (SiO₂)

Quartz fragment (likely milky quartz)

Quartz, silicon dioxide (SiO₂)

Titanium Amethyst Geode

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

Weathered granite pebble

Granite, a quartz–feldspar–mica intrusive rock

Limonite (Iron Ore)

Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)

Quartz Druzy

Silicon Dioxide (SiO2)

Pyrite-bearing sulfide specimen

Pyrite (FeS₂), possibly with chalcopyrite and weathered sulfides

Basalt with an orange mineral vein

Fine-grained basalt, likely containing iron-stained calcite or zeolite; exact identification requires testing

Conglomeratic gravel / pebble-rich concrete-like rock

Polymictic conglomerate (likely an unconsolidated gravel surface; exact identification uncertain from the image)

Iron-Stained Quartz

Silicon Dioxide with Iron Oxide (SiO2)

Red Sandstone Pebble

Sedimentary quartz sandstone

Moqui Marble (Shaman Stone)

Iron Oxide Concretion (Hematite/Goethite shell with Sandstone core)

Quartz-rich mineral specimen, possibly druzy quartz with iron staining

Quartz (SiO₂), possibly coating a vesicular host rock

Yellow-green aventurine or serpentine pendant

Most likely serpentine-group mineral (magnesium silicate), possibly quartz-rich aventurine

Milky quartz vein rock

Quartz, SiO₂; likely massive vein quartz with iron-oxide staining

Botryoidal Quartz Cluster (Druzy Stalactitic Quartz)

Silicon Dioxide (SiO2)

Tumbled, iron-stained quartz-rich pebble

Likely quartz/chalcedony with iron-oxide staining; exact rock type cannot be determined from the image

Botryoidal quartz (likely chalcedony/agate)

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

Red Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3)

Limonite with Goethite

Iron Hydroxide Mixture (FeO(OH)·nH2O)

Quartz geode or drusy quartz cluster

Quartz (silicon dioxide, SiO₂), likely a quartz-lined cavity in host rock

Quartz geode/drusy quartz

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

Titanium Aura Quartz

Silicon Dioxide (SiO2) coated with Titanium and Niobium

Manganese-coated Sandstone

Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)

Weathered Pyrite Nodule

Iron Sulfide (FeS2) undergoing oxidation to limonite/goethite

Botryoidal calcite specimen

Calcite, CaCO₃, with possible dolomite or other carbonate matrix

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂)