Crystal

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Emerald (green gemstone in a jewelry setting)

Beryl, Be₃Al₂(SiO₃)₆; green color commonly from chromium and/or vanadium

Raw aquamarine (likely beryl)

Beryl, Be₃Al₂Si₆O₁₈; blue color from iron impurities

Quartz Crystal Cluster in Matrix

Silicon Dioxide (SiO2)

Amethyst

Quartz (SiO2) with iron impurities

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Quartz crystal fragment

Quartz (silicon dioxide, SiO₂)

Amethyst crystal cluster

Amethyst, purple variety of quartz (SiO₂)

Pyrite in Matrix

Iron Sulfide (FeS2)

Amethyst Sphere

Crystalline Quartz (SiO2 with iron impurities)

Smoky Quartz

Quartz (Silicon Dioxide) - SiO2

Diamond (likely facet or crystal shard)

Diamond (C)

Milky quartz

Quartz (SiO₂)

Quartz (Pink/Rose Quartz or Quartz Crystal)

Silicon Dioxide (SiO2)

Aquamarine

Beryl (Be3Al2Si6O18)

Blue gemstone ring (likely sapphire)

Likely corundum, Al₂O₃; the dark, reflective appearance may also indicate a treated or synthetic stone.

Quartz crystal cluster

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

Blue crystal pendant (likely blue glass or synthetic crystal)

Not identifiable from the image; possibly synthetic quartz or glass, rather than a natural mineral

Amethyst (rough crystal)

Quartz, SiO₂; purple coloration typically results from trace iron and natural irradiation

White quartz crystal cluster

Quartz (silicon dioxide, SiO₂), likely milky quartz

Herkimer Diamond in Matrix

Quartz (SiO2) in Dolostone (CaMg(CO3)2)

Cut colorless gemstone, likely quartz or glass imitation

Most plausibly rock crystal (clear quartz, SiO₂); synthetic glass cannot be ruled out from the image

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Raw pale-green crystal, likely fluorite

Fluorite (calcium fluoride, CaF₂)

Quartz Crystal Cluster with Iron Stain

Silicon Dioxide (SiO2)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Clear Quartz Crystal

Silicon Dioxide (SiO2)

Yellow quartz fragment (likely citrine or iron-stained quartz)

Quartz, silicon dioxide (SiO₂), trigonal crystal system

Quartz crystal cluster in matrix

Silicon dioxide (SiO2)

Clear Quartz Crystal

Quartz (Silicon Dioxide, SiO2)

Selenite (Giant Crystals)

Selenite (CaSO4·2H2O)

Likely rough quartz crystal

Quartz (SiO₂); exact variety is uncertain from the photo

Quartz Crystal Matrix

Silicon Dioxide (SiO2)

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Tourmaline crystals

Elbaite tourmaline; complex boron silicate, commonly approximated as Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Quartz crystal cluster

Quartz, SiO₂; likely a drusy quartz cluster with small prismatic crystals

Honey quartz crystal cluster

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

Quartz with a pale pink crystal

Quartz, SiO₂; likely milky quartz with iron-stained or faintly pink quartz

Tumbled Amethyst and Smoky Quartz

Silicon Dioxide (SiO2) with impurities

Green Aventurine

Quartz (SiO2) with fuchsite inclusions

Citrine (Heat-Treated Amethyst)

Silicon Dioxide (SiO2) with ferric iron impurities

Tumbled Citrine

Silicon Dioxide (Quartz variety)