Basalt
Basalt (Mafic Extrusive Igneous Rock)
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Basalt (Mafic volcanic rock)
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
Basalt
Basalt (High-iron/magnesium silicate rock)
Quartz (Clear / Rock Crystal)
Silicon Dioxide (SiO2)
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Sandstone
Quartz Sandstone (predominantly)
Concrete Fragment
Hardened Portland Cement Composite
Milky Quartz in Matrix
Silicon Dioxide (SiO2)
Basalt (Vesicular)
Basalt (mostly plagioclase, pyroxene, and olivine)
Basalt
Basalt
Yellow Jasper (Chert variant)
Silicon Dioxide (SiO2) with iron oxide inclusions
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Basalt with Vesicles
Vesicular Basalt (comprising Plagioclase Feldspar, Pyroxene, and Olivine)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Chert Geode with Quartz Druzy
Microcrystalline Quartz (SiO2) with macrocrystalline Quartz
Pink Granite (Crystalline Granite)
Igneous Intrusive Rock (Felsic Plutonic)
Banded Agate (specifically Botswana Agate or Water-line Agate)
Chalcedony (cryptocrystalline variety of Quartz), SiO2
Orange Calcite
Calcium Carbonate (CaCO3)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Ferruginous Sandstone
Sandstone with iron oxide (Hematite/Limonite) cement
Blue Lace Agate (Polished Point)
Silicon Dioxide (SiO2) - Variety of Chalcedony
Agate
Banded Chalcedony (SiO2)
Scoria (Lava Rock)
Scoria (Mafic volcanic rock)
Scoria (Vesicular Basalt)
Scoria (Vesicular Igneous Rock)
Basalt
Extrusive mafic igneous rock
Honey Calcite
Calcium Carbonate (CaCO3)
Zebra Jasper
Silicon Dioxide (SiO2) with impurities; typically a form of Chalcedony/Microcrystalline Quartz
Quartz (Crystal/Druzy Quartz)
Quartz (SiO₂)
Metaconglomerate
Metaconglomerate (Quartzite conglomerate)
Granite
Phaneritic Plutonic Igneous Rock (primarily composed of quartz, alkali feldspar, and plagioclase)
Sandstone or Limestone
Sedimentary Rock
Basalt
Basalt (primarily Plagioclase feldspar and Pyroxene)
Chalcedony (specifically Agate or Carnelian pebble)
Chalcedony (Microcrystalline Quartz, SiO2)
Hypersthene
Hypersthene ((Mg,Fe)SiO₃)
Chert (specifically Gray/Blue-Gray Chert)
Chert (SiO2)
Pumice
Pumice (Vesicular Rhyolite/Andesite)
Green Calcite
Calcium Carbonate (CaCO3)
Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)
Chalcedony (SiO₂)
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
Mookaite Jasper
Radiolarite (Silica, SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite or Iron Oxide inclusions