Mineral Specimen

Pyrite in Quartz

Iron Sulfide (FeS2) with Silicon Dioxide (SiO2)

Jasper

Microcrystalline Quartz (SiO2)

Quartz with Schorl inclusions

Silicon Dioxide (SiO2) with Sodium Iron Aluminum Borosilicate Hydroxide (Black Tourmaline)

Rose Quartz

Silicon Dioxide (SiO2)

Calcite in Matrix

Calcium Carbonate (CaCO3) on Sedimentary Host Rock

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide inclusions (Hematite/Goethite)

Amazonite

Tectosilicate (variety of Microcline), K(AlSi3O8)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Beryl (likely Aquamarine or Green Beryl)

Beryllium aluminum silicate (Be3Al2Si6O18)

Aquamarine

Beryl (Be3Al2Si6O18) with trace Iron (Fe2+)

Black Tourmaline (Schorl)

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

Emerald In Matrix (Quartz/Calcite)

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Magnetite

Iron(II,III) oxide (Fe3O4)

Quartz (Druzy/Macro-crystalline)

Silicon Dioxide (SiO2)

Amethyst crystal fragment

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation

Petrified Wood

Silicified wood (primarily SiO2 - Silicon Dioxide/Quartz)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Quartz with Host Rock Matrix

Silicon Dioxide (SiO2)

Carnelian Agate

Silicon Dioxide (SiO2) - variety of Chalcedony

Amethyst (rough quartz)

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

Unidentified gray mineral/rock fragment

Indeterminate from image; possibly quartz-rich material or mica-bearing schist

Small white mineral fragment

Indeterminate; possibly quartz, calcite, or feldspar

Small quartz-rich stone, possibly granite fragment

Indeterminate; likely quartz (SiO₂) with feldspar and/or mica

Granite (likely pegmatitic granite)

Felsic intrusive igneous rock, primarily quartz, feldspar, and mica

Tumbled quartz-rich stone, possibly druzy quartz or quartzite

Quartz (SiO₂), likely in a quartzite or chalcedonic matrix

Scoria with Calcite Infills

Vesicular Basalt with secondary Calcification (CaCO3)

Milky Quartz (with Iron Staining)

Silicon Dioxide (SiO2)

Amethyst

Amethyst (Varietal of Quartz), SiO2 with traces of Iron (Fe3+)

Tumbled amethyst and likely smoky quartz inclusion specimen

Amethyst: purple quartz, SiO₂; left stone appears quartz-rich with brown iron-oxide inclusions, possibly “garden quartz” or included smoky quartz

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Greenish translucent mineral fragment

Indeterminate; possibly serpentine, epidote, or green glassy feldspar

Pyrite

Iron Sulfide (FeS2)

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Green Quartzite

Meta-quartzite with fuchsite or chlorite inclusion

Quartz Cluster

Silicon Dioxide (SiO2)

Sunstone

Plagioclase Feldspar (Oligoclase or Andesine) - (Na,Ca)(Si,Al)3O8

Smoky Quartz

Silicon Dioxide (SiO2)

Pink halite (rock salt)

Halite, sodium chloride (NaCl)

Amethyst

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

Quartz crystal cluster

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

Polished black tourmaline

Schorl tourmaline — NaFe3Al6(BO3)3Si6O18(OH)4

Tree Agate

Chalcedony (SiO2)