Basalt
Basalt (Mafic volcanic rock)
igneous
Category
Mineral, Often A Rock Given Its Aggregate Nature
Browse mineral, often a rock given its aggregate nature specimens identified by the Rock Identifier community.
Sandstone (Tumbled/River Pebble)
Arenite (composed primarily of SiO2)
sedimentary
Herkimer Diamond in Matrix
Quartz (SiO2) in Dolostone (CaMg(CO3)2)
sedimentary (host) / mineral (crystals)
Slag (Industrial Glass/Metal)
Ferrous slag or Glassy silicate byproduct
Antropogenic rock (Man-made)
Red Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Dyed Quartzite
Tumbled Metamorphosed Quartz (SiO2) with artificial pigment
metamorphic
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Unakite
Unakite (Metasomatized Granite)
metamorphic
Granitic Gravel Piece
Granite (Felsic Plutonic Rock / SiO2 with Al2O3, K2O, Na2O)
igneous
Chert (specifically Flint or Jasper-Chert)
Silicon Dioxide (SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2)
sedimentary
Basalt
Basalt
igneous
Jasper (Red/Brown)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Conglomerate (River Rock)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Basalt
Basalt (Mafic volcanic rock)
igneous
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
mineral
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt
igneous
Magnetite
Magnetite (Fe3O4)
mineral
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
sedimentary
Conglomerate
Conglomerate (Detrital sedimentary rock)
sedimentary
Chert (specifically Tan/Gray Chert)
Microcrystalline quartz (SiO2)
sedimentary
Conglomerate with Quartzite Pebbles
Clastic sedimentary rock (Conglomerate)
sedimentary
Conglomerate
Clastic sedimentary rock (Conglomerate)
sedimentary
Amethyst on Agate/Basalt Matrix
Silicon Dioxide (SiO2) with iron impurities
mineral
River Rock (likely Siltstone or fine-grained Sandstone)
Clastic Sedimentary Rock
sedimentary
Asphalt (Bituminous Pavement Bit)
Bitumen-bound aggregate (Petrochemical-bound composite)
sedimentary (anthropogenic/technogenic)
Asphalt (Bituminous pavement fragment)
Artificial conglomerate / Bitumen-Aggregate mixture
sedimentary
Granite
Granite (a plutonic igneous rock composed primarily of quartz and feldspar)
Igneous Rock
Banded Rhyolite (likely Green Jasper/Agate variety)
Silicon Dioxide (SiO2) with mineral inclusions
igneous
Limonite (often after Hematite or Goethite)
Limonite (FeO(OH)·nH2O)
mineral
Basalt with Vesicles
Vesicular Basalt (comprising Plagioclase Feldspar, Pyroxene, and Olivine)
igneous
Sandstone with Concretions / Liesegang Rings
Arenite with iron oxide banding
sedimentary
Quartzite Pebble (with Iron Inclusions)
Metamorphic Rock (Mainly SiO2)
metamorphic
Sandstone
Arenite (SiO2 dominant)
sedimentary
Basalt (Arrowhead form)
Extrusive mafic igneous rock
igneous
Quartz (likely Milky Quartz or Chalcedony)
Quartz (SiO2 - Silicon Dioxide)
Mineral
Sandstone (likely Arkosic)
Clastic Sedimentary Rock
sedimentary
Chert Geode or Nodule
Microcrystalline Quartz (SiO2)
sedimentary
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Jasper
Silicon dioxide (SiO2)
sedimentary