Quartz (Milky/Granular)
Silicon Dioxide (SiO2)
Category
Browse organic (non rock) specimens identified by the Rock Identifier community.
Quartz (Milky/Granular)
Silicon Dioxide (SiO2)
Quartz / Common Opal
Silicon Dioxide (SiO2)
Green Aventurine
SiO2 (Silicon Dioxide with inclusions of Fuchsite mica)
Red Sandstone
Arenite (primarily Quartz SiO₂ with Hematite Fe₂O₃ staining)
Greywhacke (River Pebble)
Graywacke (immature sandstone)
Sandstone (Quartzose Sandstone)
Arenite (composed primarily of SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Amethyst (Faceted)
Quartz (SiO2) with iron impurities
Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Smoky Quartz with Feldspar
Quartz (SiO2) with Potassium Feldspar (KAlSi3O8)
Coquina
Bioclastic Limestone
Quartz Geode
Silicon Dioxide (SiO2)
Iron Ore (Limonite and Hematite)
Goethite/Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)
Specular Hematite
Specularite (Fe2O3)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Basalt
Basalt (Mafic volcanic rock)
Basalt River Rock
Basalt (Aphanitic Mafic Igneous Rock)
Quartzite
Quartzite (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Quartzite
Quartzite (primarily SiO2)
Quartzite
Quartzite (SiO2)
Basalt
Basalt
Quartz Geode (Cracked Open)
Quartz (Silicon Dioxide - SiO2)
Unakite
Unakite (Epidotized Granite)
Unakite
Unakite (Episyenite composition: Feldspar, Epidote, and Quartz)
Polished Basalt
Basalt (Mafic volcanic rock)
Quartzite
Quartzite (primarily SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Amethyst (Polished Point)
Crystalline Quartz (SiO2 with iron impurities)
Bixbyite on Rhyolite
Bixbyite (Mn2+,Fe3+)2O3
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
Bloodstone (Heliotrope)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Carnelian Agate
Silicon Dioxide (SiO2) with Hematite inclusions
Quartz Pebble
Silicon Dioxide (SiO2)
Blue Sapphire (in a faceted jewelry setting)
Corundum (Al2O3) with trace Iron and Titanium
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Gold Nugget
Native Gold (Au)
Chalcedony (Agate)
Silicon Dioxide (SiO2)
Garnet
Garnet Group (Silicate Minerals), formula varies e.g., Almandine Fe3Al2(SiO4)3
Carnelian
Carnelian (SiO2)
Amethyst (Quartz)
Silicon Dioxide (SiO2) with iron impurities