Crystal

Moss Agate

Silicon Dioxide (Chalcedony variety)

Amethyst stalactite slice pendant

Amethyst (紫 quartz), SiO₂, with concentric quartz/chalcedony and likely agate banding

Aquamarine (Tumbled)

Beryl (Be3Al2Si6O18)

Amethyst (rough crystal specimen)

Quartz, SiO₂; purple coloration commonly caused by trace iron and natural irradiation

Banded calcite crystal tower

Calcite (CaCO₃), likely honey or brown banded calcite

Clear quartz crystal fragments

Quartz (silicon dioxide, SiO₂)

Blue-green apatite crystal in matrix

Apatite-group phosphate, commonly fluorapatite (Ca₅(PO₄)₃F)

Quartz crystal (likely iron-stained quartz)

Quartz, SiO₂

Quartz crystal pendant (likely smoky quartz or iron-stained quartz)

Quartz, silicon dioxide (SiO₂)

Small gold-colored mineral crystal, likely pyrite

Pyrite (FeS₂), tentatively; native gold is a less likely alternative

Clear quartz crystal (likely tumbled or naturally worn)

Quartz, silicon dioxide (SiO₂)

Iridescent red crystal cluster, likely aura-coated quartz

Quartz (SiO₂), possibly metal-coated; exact identification is uncertain from the photo

Small purple quartz crystal, likely amethyst

Amethyst: violet variety of quartz, silicon dioxide (SiO₂)

Emerald in Matrix (Tumbled)

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Geode with Quartz Crystal Cavity

Silicon Dioxide (SiO2) in Calcareous/Siliceous Matrix

Gypsum crystal cluster (selenite)

Gypsum, CaSO₄·2H₂O; likely a radiating selenite crystal formation

Quartz crystals on matrix

Silicon dioxide (SiO2)

Quartz geode slice

Microcrystalline quartz (SiO₂), chiefly chalcedony with drusy quartz crystals

Quartz (Citrine or Iron-Stained)

SiO2

Aura Quartz (Pink/Magenta Aura Quartz)

Silicon Dioxide (SiO2) treated with vapor-deposited precious metals

Colorless faceted gemstones, likely quartz (rock crystal)

Quartz, silicon dioxide (SiO₂), trigonal crystal system

Rock Crystal (Clear Quartz)

Silicon dioxide (SiO2)

Druzy Quartz on Quartz Base

Silicon Dioxide (SiO2)

Clear quartz crystal

Quartz (silicon dioxide, SiO₂)

Rough Quartz Crystal in Matrix

Silicon Dioxide (SiO2)

Snowflake obsidian

Volcanic glass (silica-rich rhyolitic composition), commonly with cristobalite inclusions

Milky quartz

Quartz (silicon dioxide, SiO₂)

Orgonite Pyramid (containing Amethyst and mixed minerals)

Silicon Dioxide (SiO2) in synthetic resin

Clear Quartz Crystal (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Emerald in Matrix

Beryllium Aluminum Silicate (Be3Al2Si6O18) with Chromium/Vanadium impurities

Aquamarine

Beryl (Be3Al2Si6O18 with trace Fe2+)

Emerald

Beryl (Be3Al2Si6O18) with trace amounts of Chromium and/or Vanadium

Clear quartz crystal pendant

Quartz (silicon dioxide, SiO₂)

Aquamarine

Beryl (Be3Al2Si6O18)

Blue-green rough crystal, possibly aquamarine

Possibly beryl (Be₃Al₂Si₆O₁₈); the image is insufficient for a definitive identification

Small rough quartz crystal or quartz fragment

Quartz (silicon dioxide, SiO₂)

Likely rough feldspar crystal (possibly amazonite or orthoclase)

Potassium feldspar, KAlSi₃O₈; exact variety cannot be confirmed from the image

Raw quartz crystal cluster (likely chalcedony/quartz)

Quartz, silicon dioxide (SiO₂)

Quartz geode/drusy quartz cluster

Quartz (SiO₂), with probable feldspar host and minor iron-oxide staining

Polished/polished rough quartz crystal, likely hematoid or included quartz

Quartz (SiO₂), with probable iron-oxide inclusions; possibly smoky or rose-tinted quartz

Heliodor (Yellow Beryl) / Greenish-Yellow Beryl

Beryl (Be3Al2Si6O18)

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities