Igneous Or Sedimentary

Gneiss (Banded Gneiss)

Gneiss

Carnelian

Carnelian (a variety of Chalcedony); SiO2 (Silicon Dioxide)

Quartz (Crystalline Cluster)

Silicon Dioxide (SiO2)

Banded gneiss pebble

Gneiss, likely quartz–feldspar–mica gneiss

Banded Gneiss with Quartz Vein

Gneiss containing SiO2 (Quartz) intrusion

Gneiss

Gneiss

Concrete or asphalt-like aggregate surface with a dark fragment

Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock

Gneiss (High-Grade Metamorphic Rock)

Gneiss (primarily composed of Quartz, Feldspar, and Mica/Amphiboles)

Gneiss

High-grade Metamorphic Gneiss

Gneiss

Gneiss (Metamorphic high-grade)

Banded metamorphic rock, likely gneiss or banded amphibolite

Undetermined foliated metamorphic rock; commonly quartz–feldspar–biotite gneiss or amphibolite

Green Fluorite

Calcium Fluoride (CaF2)

Epidote

Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Carnelian

Silicon Dioxide (SiO2) - variety of Chalcedony

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Banded gneiss (likely weathered paragneiss)

Gneiss; quartz–feldspar–mica ± amphibole assemblage

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Banded Gneiss

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

Chalcedony (Agate/Carnelian precursor)

Chalcedony (Silicon Dioxide, SiO2)

Gneiss

Gneiss (High-grade regional metamorphic rock)

Banded Gneiss

Metamorphic Gneiss (High-grade regional metamorphism specimen)

Gneiss (High-grade Metamorphic Rock)

Gneiss (Metamorphic silicate rock)

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Carnelian

Carnelian (SiO2, Silicon Dioxide with Iron Oxide impurities)

Gneiss (specifically a Banded Gneiss cobble)

Gneiss (composed mainly of Quartz, Feldspar, and Biotite/Amphibole)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Quartz Druze on Matrix (Geode Fragment)

Quartz (Silicon Dioxide, SiO2)

Banded metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss, possibly amphibolite-bearing

Gneiss

Gneiss (High-grade Metamorphic Rock)

Gneiss

Gneiss

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Nuummite

Nuummite (Orthoamphibole rock / Anthophyllite-Gedrite blend)

Epidote with Magnetite/Hematite inclusions

Epidote (Ca2(Al2,Fe3+)(SiO4)3(OH)) with Iron Oxides

Banded Gneiss

Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Mica)

Banded Gneiss

Gneiss (Metamorphic Rock)

Banded Gneiss and Siltstone River Stones

Gneiss (High-grade Metamorphic Rock)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Gneiss (Schistose)

Gneiss

Carnelian

Carnelian (Silicon Dioxide - SiO2)

Carnelian

Cryptocrystalline Quartz (SiO2 with iron oxide impurities)

Bloodstone Jasper (Heliotrope)

SiO2 (Silicon Dioxide) - Cryptocrystalline Quartz