Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
Muscovite Mica
Muscovite / KAl2(AlSi3O10)(OH)2
Blue Chalcedony
Silicon Dioxide (SiO2)
Kyanite in Quartz
Kyanite (Al2SiO5) with Quartz (SiO2)
Gneiss (with Quartz and Mica)
Gneiss
Basalt with Magnetite
Crystalline Basalt (Primarily Plagioclase and Pyroxene) with Magnetite (Fe3O4)
Amethyst (Tumbled)
Purple Quartz (SiO2 with iron impurities and irradiation)
Unakite
Epidote-Feldspar rock (specifically, a variety of granite)
Fossiliferous Rock (likely Dinosaur Fossil in Matrix)
Permineralized Vertebrate Fossil (Calcium Carbonate/Silica replaced bone material)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Greenstone
Greenschist (metamorphosed mafic igneous rock)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Granite (Pink/Potassium Feldspar Granite)
Felsic Plutonic Rock (Potassium Feldspar, Quartz, Mica, and Amphibole)
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
Ironstone Concretion (Limonite/Goethite)
Ironstone (primarily FeO(OH)·nH2O)
Gneiss
Gneiss
Graywacke
Graywacke
Chevron Amethyst
Silicon Dioxide (SiO2) with iron impurities
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Agate
Agate (a variety of Chalcedony, SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Banded Agate (with small Geode cavity)
Silicon Dioxide (SiO2) - Chalcedony variety
Conglomerate
Conglomerate (a clastic sedimentary rock)
Jasper Quarzite (possibly Lake Superior Agate mix)
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
Gneiss (specifically a Banded Gneiss pebble)
Gneiss (High-grade Regional Metamorphic Rock)
Clear Quartz
Silicon Dioxide (SiO2)
Carnelian
Carnelian (a variety of Chalcedony), SiO2 (Silicon Dioxide)
Blue Chalcedony
Silicon Dioxide (SiO2)
Ironstone Concretion / Limonite Node
Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O) with Goethite/Hematite
Septarian Nodule
Septarian Nodule (Mixture of Calcite, Aragonite, and Limestone/Clay)
Amethyst Geode/Cluster
Quartz (SiO2) - variety Amethyst
Jasper (specifically Red Jasper)
Silicon Dioxide with Iron Oxides (SiO2 + Fe2O3)
Rhyolite
Rhyolite (Extrusive Igneous Rock)
Jasper (specifically variegated or swamp jasper beads)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Limestone
Calcium Carbonate (CaCO3)
Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
Quartz (Drusy/Crystalline)
Silicon Dioxide (SiO2)
Blue Chalcedony
Cryptocrystalline Quartz (SiO2)
Pink Granite
Granite (composed primarily of Quartz, K-Feldspar, and Plagioclase)
Gneiss
Gneiss (High-grade metamorphic rock)
Pink Granite
Granite (Phaneritic igneous rock)
Grey Chalcedony
Silicon Dioxide (SiO2)