Sedimentary Or Metamorphic

Gneiss (with Quartz-Feldspar vein)

Gneiss (high-grade metamorphic rock) containing Quartz (SiO2) and Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8)

Gneiss

Gneiss

Quartzite

Quartzite (primarily SiO2)

Gneiss (Banded Gneiss)

Gneiss

Quartz Pebble

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Rough Garnet in Matrix

Almandine Garnet (Fe3Al2Si3O12)

Banded Gneiss

Gneiss (Metamorphic rock composed of feldspar, quartz, and mica)

Green Aventurine

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

Green Aventurine

Quartzite (Silicon Dioxide, SiO2 + Fuchsite)

Gneiss

Gneiss

Ferruginous Quartz (Iron-stained Quartzite)

Silicon Dioxide (SiO2) with iron oxide inclusions

Greenstone / Graywacke

Metagraywacke (Chlorite-grade schistose rock)

Titanium Coated Kyanite (Aura Kyanite)

Aluminosilicate (Al2SiO5) with a Titanium-Niobium vacuum-deposited coating

Gneiss (Granitic Gneiss)

Gneiss (from German Gneis, related to 'spark')

Quartzite

Quartzite (primarily SiO2)

Quartzite River Rock (with Limonite staining)

Quartzite (SiO2)

Greenstone / River Siltstone

Metasedimentary Greenstone (Chlorite-rich Siltstone)

Foliated Gneiss (River-Worn Pebble)

Gneiss (High-grade Regional Metamorphic Rock)

Gneiss

Gneiss (High-grade regional metamorphic rock)

Gneiss

Gneiss (High-grade regional metamorphic rock)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Quartz Pebble

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

Nephrite Jade

Nephrite (a variety of the mineral actinolite within the amphibole group); Chemical Formula: Ca2(Mg,Fe)5Si8O22(OH)2

Granite Gneiss

Gneiss (High-grade regional metamorphic rock)

Quartzite

Quartzite (primarily SiO2)

Gneiss (Schistose)

Gneiss

Gneiss

Gneiss

Quartzite (Rounded Pebble)

Quartzite (predominantly SiO2)

Gneiss

Gneiss

Banded Gneiss

Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Biotite/Amphiboles)

Gneiss (specifically a Granitic Gneiss)

Gneiss (Composition: Quartz, Feldspar, Mica)

Mica Schist with Iron Staining

Mica Schist

Garnet (Almandine variety)

Almandine, Fe3Al2(SiO4)3

Arkosic Sandstone (or Conglomeritic Sandstone fragment)

Arkose (rich in feldspar)

Coarse Sand Grain / Lithic Fragment

Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)

Petrified Wood

Silicified Wood (primarily SiO2)

Gneiss (Granitic Gneiss)

Gneiss

Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Gneiss

Gneiss (High-grade regional metamorphic rock)