Sandstone
Arenite (Sedimentary rock composed of sand-sized grains, primarily SiO2)
Category
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
Sandstone
Arenite (Sedimentary rock composed of sand-sized grains, primarily SiO2)
Sandstone (Micaceous/Feldspathic variant)
Arenite (specifically subarkose or lithic arenite)
Sandstone (with Liesegang rings or Oxidation)
Arenite (primarily Quartz SiO2 with Iron Oxide Fe2O3 staining)
Greenstone / Quartzite Pebble
Metamorphosed Quartz-rich Rock
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Granite
Granite
Metagabbro / Epidote Gneiss
Epidote bearing Hornblende Gneiss
Quartz with Iron Staining
Silicon Dioxide (SiO2)
Granodiorite
Granodiorite (Na,Ca)(Si,Al)4O8
Chert (often called Flint or Jasper)
Cryptocrystalline quartz (SiO2)
Massive Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon dioxide (SiO2)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Quartz (with iron oxide staining)
Silicon Dioxide (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Shale
Shale (composition varies: primarily clay minerals and quartz)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Smoky Quartz (with possible Garnet inclusions)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Amber
Succinite (specific to Baltic amber), fossilized tree resin
Milky Quartz
Silicon Dioxide (SiO2)
Blue Quartzite
Quartzite (primarily SiO2) with inclusions like Dumortierite or Magnesio-riebeckite
Obsidian
Volcanic Glass (SiO2)
Azurite
Azurite (Cu3(CO3)2(OH)2)
Amethyst
SiO2 (Silicon Dioxide)
Amazonite
K(AlSi3O8) - Lead-bearing Microcline (Potassium Feldspar)
Quartz Geode (Druzy)
Crystalline Silicon Dioxide (SiO2)
Chert (Quartz)
Microcrystalline Silica (SiO2)
Amber
Succinite (a fossilized organic resin containing succinic acid)
Quartz (Smoky/Milky Variety)
Silicon Dioxide (SiO2)
Banded Agate
Cryptocrystalline Quartz (SiO2)
Eye Agate
Silicon Dioxide (SiO2) - Banded Chalcedony
Bull Quartz
Quartz (Silicon Dioxide - SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Jasper (brecciated or orbicular variety)
Silicon dioxide (SiO2) with iron oxide inclusions
Diorite
Phaneritic Intermediate Igneous Rock
Red Granite
Phaneritic Felsic Igneous Rock
Yellow Quartzite (River Pebble)
Quartzite (SiO2)
Greenstone / Serpentinite
Serpentinite (composed primarily of minerals from the serpentine group Mg3Si2O5(OH)4)