Metamorphic (Low Grade)

Gneiss

Gneiss (pronounced 'nice')

Tanzanite

Blue-violet Zoisite (Ca2Al3(SiO4)3(OH))

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Biotite Mica

K(Mg,Fe)3AlSi3O10(OH)2

Labradorite

(Ca, Na)(Al, Si)4O8 (Plagioclase Feldspar)

Banded Gneiss

Gneiss (pronounced 'nice')

Calcite

Calcite (CaCO₃)

Quartz

Quartz (Silicon Dioxide, SiO2)

Ruby

Corundum (Al2O3 with Chromium traces)

Ironstone Concretion (likely)

Goethite/Hematite/Limonite cemented sediment

Citrine

Quartz (SiO2) - variety Citrine

Amethyst

Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities

Dendritic Agate

Silicon Dioxide with Manganese or Iron Oxide inclusions (SiO2 + Mn/Fe)

Ruby in Zoisite

Ruby (α-Al2O3) embedded in Zoisite (Ca2Al3(SiO4)3(OH)) with some Hornblende

Fluorite Bracelet (light green beads) and possibly Lavender Jadeite (purple bead)

Fluorite: CaF₂ (Calcium Fluoride); Jadeite: NaAlSi₂O₆ (Sodium Aluminum Silicate)

Yellow Chalcedony

Chalcedony (a cryptocrystalline variety of Quartz, SiO₂)

Amethyst

Quartz (SiO2) variety

Calcite

Calcite (CaCO3)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Amethyst (Geode Fragment)

Silicon Dioxide (SiO2 with iron impurities)

Black Star Diopside

Diopside (CaMgSi2O6) with Magnetite inclusions

Mica-rich Sandstone or Micaceous Schist Weathering

Micaceous Schist (Muscovite-Quartz composition)

Blue Tiger's Eye

Riebeckite (crocidolite variety)

Anthracite Coal

Anthracite (a form of coal, primarily carbon)

Serpentinite

Serpentinite (composed primarily of serpentine-group minerals like antigorite, chrysotile, and lizardite; chemical formula varies but generally Mg3Si2O5(OH)4)

Calcite

Calcite (CaCO3)

Pyrite

Pyrite (Iron Disulfide), FeS2

Blue Lace Agate

Chalcedony (a form of Quartz) - SiO2

Green Calcite

Calcite (CaCO3)

Gneiss

Gneiss (a rock type, not a specific mineral with a formula)

Pyrite (or Fool's Gold)

Pyrite (FeS₂)

Marble

Marble (primarily Calcite, CaCO3 or Dolomite, CaMg(CO3)2)

Fluorite

Fluorite (Calcium Fluoride, CaF2)

Quartz with Mica/Chlorite inclusions

Silicon Dioxide (SiO2) with phyllosilicate inclusions

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Sapphire (Corundum)

Corundum (Al2O3), variety Sapphire

Fluorite (likely)

Calcium Fluoride (CaF2)

Serpentinite (Serpentine Rock)

Serpentinite is a rock composed of one or more serpentine group minerals, chiefly antigorite, chrysotile, and lizardite, with the general formula (Mg,Fe)3Si2O5(OH)4. Often includes other minerals like magnetite, talc, and chromite.

Banded Gneiss

Gneiss (pronounced "nice")

River Stone / Pebble

Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)

Lapis Lazuli

Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)₈[(S,Cl,SO₄,OH)₂|(Al₆Si₆O₂₄)], with varying amounts of Calcite, Pyrite, and Sodalite.)

Serpentine

Serpentine group minerals (e.g., Antigorite, Chrysotile, Lizardite). Chemical formula: (Mg, Fe)₃Si₂O₅(OH)₄