Crystal

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Clear quartz crystal

Quartz (silicon dioxide, SiO₂)

Clear Quartz Crystal

Silicon dioxide (SiO2)

Quartz Crystal Cluster (with Selenite Satin Spar)

Silicon Dioxide (SiO2)

Obsidian

Volcanic glass (Amorphous silicon dioxide)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Amethyst geode fragment

Quartz, SiO₂, colored by trace iron; purple quartz crystals lining a geode cavity

Clear quartz sphere

Quartz (silicon dioxide, SiO₂), likely rock crystal or low-grade milky quartz

Diamond in Kimberlite

Kimberlite Matrix with Carbon (Diamond)

Smoky Quartz and Feldspar Pegmatite

Granitic Pegmatite (chiefly SiO2 and KAlSi3O8)

Small pale-yellow crystal, possibly quartz

Unidentified translucent mineral; quartz (SiO₂) is one possibility, but the image is insufficient for reliable identification.

Clear Quartz (Rock Crystal) Bead

Silicon Dioxide (SiO2)

Radiating stibnite crystals

Stibnite (antimony sulfide, Sb₂S₃)

Quartz crystal cluster

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

Raw quartz crystal/chunk

Quartz (silicon dioxide, SiO₂)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Quartz (SiO₂)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Pink tourmaline (likely rubellite), faceted gemstone

Elbaite tourmaline, Na(Li₁.₅Al₁.₅)Al₆Si₆O₁₈(BO₃)₃(OH)₄

Tumbled Clear Quartz/Rock Crystal

Silicon Dioxide (SiO2)

Quartz-rich stone, likely quartzite or milky quartz

Quartzite; predominantly silicon dioxide (SiO₂)

White Quartz Pebble

Silicon Dioxide (SiO2)

Rose Quartz

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

Amethyst

Quartz (Silicon Dioxide, SiO2)

Diamond (Uncut Crystal)

Carbon (C)

Quartz (Rock Crystal)

Quartz (SiO₂ - Silicon Dioxide)

Quartz Crystal with Inclusions

Silicon Dioxide (SiO2)

Rough Quartz (Clear Quartz)

Silicon Dioxide (SiO2)

Pyrite on Quartz (Fool's Gold in Quartz)

Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)

Pyrite (Iron Pyrite)

Iron Disulfide (FeS2)

Feldspar-rich Pegmatite

Granitic Pegmatite (principally KAlSi3O8)

Black Obsidian

Volcanic Glass (SiO2 with impurities)

Quartz crystal cluster in matrix

Quartz (SiO₂), likely in a feldspar- and mica-bearing pegmatite

Milky Quartz Beads

SiO2 (Silicon Dioxide)

Calcite crystal cluster

Calcite, calcium carbonate (CaCO₃)

Pyrite-bearing rock (likely pyrite-rich sulfide ore)

Pyrite, FeS₂, with possible dark host rock; exact matrix is not identifiable from the photo

Amethyst quartz cluster

Quartz, SiO₂; purple variety colored mainly by iron impurities and irradiation

Quartz in Basalt (Xenocryst)

Silicon Dioxide (SiO2) in Mafic Igneous Volcanic Rock

Quartz Geode

Silicon Dioxide (SiO2)

Black tourmaline (schorl)

Schorl, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Quartz crystal cluster on matrix

Quartz (silicon dioxide, SiO₂), likely iron-stained or included variety