This Appears To Be A Man Made Metallic Object, Likely Jewelry, Not A Natural Rock, Mineral, Or Geological Specimen.

Chevron Amethyst

Silicon Dioxide (SiO2) with iron impurities

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Mica Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Quartz (Pebble)

Quartz (SiO₂)

Gneiss

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

Aventurine (likely Green Aventurine)

Quartz (SiO2) with included minerals (Fuchsite or Chlorite for green color)

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)

Quartz Crystal (specifically a small Clear Quartz point)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily SiO₂ / Silicon Dioxide)

Granitic Quartz with Feldspar

Granite (composed primarily of SiO2 and KAlSi3O8)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Metasedimentary or Igneous Matrix

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Dendrite (Manganese Oxide Dendrites)

Psilomelane or Pyrolusite on Matrix (typically MnO2)

Botryoidal Hematite (Kidney Ore)

Hematite (Fe2O3)

Green Aventurine

Silicon Dioxide (Quartz variety) with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Rose Quartz

Rose Quartz (SiO2)

Amazonite

KAlSi3O8 (Potassium Feldspar, variety of Microcline)

Aventurine

Silicon Dioxide (SiO2 with inclusions of Fuchsite mica)

Sunstone

Aventurine Feldspar (composition: (Ca,Na)((Al,Si)2Si2O8))

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Shale (possibly)

Shale (fine-grained clastic sedimentary rock)

Green Chalcedony (Green Agate)

Silicon Dioxide (SiO2)

Pyrite

Iron Disulfide (FeS2)

Amethyst Quartz (Tumbled)

Amethyst (Silicon Dioxide with iron impurities, SiO2)

Yellow Chalcedony

Silicon Dioxide (SiO2)

Green Moss Agate

Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite

Leopard Skin Jasper

Orbicular Rhyolite (Silicon Dioxide with various impurities)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Brown Jasper

Jasper (a cryptocrystalline variety of Quartz, SiO2)

Calcite

Calcite (Mineral, Calcium Carbonate - CaCO3)

Raw Citrine (Yellow Quartz)

Citrine / Silicon Dioxide (SiO2)

Quartz (River-worn Pebble)

Quartz (SiO2)

Chert (Grey-Green Flint)

Microcrystalline silicon dioxide (SiO2)

Druzy Quartz on Host Rock

Silicon Dioxide (SiO2)

Peridot in Basalt/Xenolith

Olivine (Mg, Fe)2SiO4 in Vesicular Basalt

Calcite

Calcite (CaCO3)

Jasper

Jasper (a variety of Chalcedony, SiO2)

Copper-bearing Mica Schist

Mica Schist with Native Copper inclusions

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)