Banded Gneiss
Gneiss (pronounced "nice")
metamorphic
Category
Mineral, Specifically A Detrital Grain
Browse mineral, specifically a detrital grain specimens identified by the Rock Identifier community.
Pyritic Quartzite
Metequartzite with FeS2 (Pyrite) inclusions
metamorphic
Basalt (River Cobble)
Mafic Igneous Basalt (composed primarily of Plagioclase feldspar, Pyroxene, and Olivine)
Igneous
Granite
Phaneritic Igneous Rock (composed mostly of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Granite (Dioritic or Hornblende-rich)
Phaneritic Plutonic Felsic to Intermediate Igneous Rock
igneous
Quartzite (Iron-stained)
Quartzite (primarily SiO2)
metamorphic
Shale (with Iron Oxide staining)
Fissile Mudstone (primarily Quartz and Clay minerals)
sedimentary
Porphyritic Basalt (with Pyrolusite or Iron-oxide staining)
Porphyritic Basalt (Mafic Extrusive)
igneous
Greenstone (Metabaltic/Greenschist)
Chlorite schist / Meta-basalt
metamorphic
Granite
Granite (primarily Quartz, Feldspar, and Mica)
igneous
Granite
Plutonic felsic igneous rock
igneous
Green Jasper with Quartz veins
Jasper (Silicon Dioxide, SiO2)
sedimentary
Diorite
Diorite
igneous
Red Sandstone
Arenite (with Iron Oxide cement)
sedimentary
Basalt with Iron Oxidation (Lattice/Veined)
Mafic Volcanic Rock (principally Plagioclase and Pyroxene)
igneous
Sandstone (with potential trace fossils)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Jasper Conglomerate
Jasper Conglomerate (SiO2 matrix with varying mineral inclusions)
sedimentary
Sandstone (Weathered Cobble)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Shale (with minor calcite veining)
Clastic sedimentary rock (primarily clay minerals and quartz)
sedimentary
Quartzite Pebble (with Iron Inclusions)
Quartzite (primarily SiO2 with Fe2O3/FeOOH impurities)
metamorphic
Basalt (Vesicular)
Extrusive mafic igneous rock; primarily (Mg, Fe)2SiO4 (Olivine), CaAl2Si2O8 (Plagioclase Feldspar), and Pyroxene
igneous
Sandstone (Ferruginous)
Arenite (Fe2O3 dominant staining)
sedimentary
Granite with Mafic Inclusions
Granite (Phaneritic igneous rock composed of Quartz, Feldspar, and Mica)
igneous
Granite
Plutonic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)
igneous
Fossiliferous Chert (with Brachiopod or Mollusk fragments)
Silicon dioxide (SiO2) with Calcium Carbonate (CaCO3) inclusions
sedimentary
Sandstone (Pebble/Cobble)
Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)
Sedimentary
Pink Granite
Granite (High K-Feldspar variety)
igneous
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Sandstone
Arenite (predominantly Quartz Sandstone)
sedimentary
Blue Chalcedony
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Schorl (Black Tourmaline)
Sodium Iron Aluminum Borosilicate Hydroxide; NaFe2+3Al6Si6O18(BO3)3(OH)3OH
mineral
Amber Agate / Carnelian
Chalcedony (Silicon Dioxide, SiO2)
mineral
Marble
Recrystallized Carbonate Rock (CaCO3)
metamorphic
Basalt with Iron Oxidation
Extrusive Mafic Igneous Rock (composed of Plagioclase and Pyroxene)
igneous
Sandstone (River Pebble)
Arenite (SiO2 based)
sedimentary
Sandstone
Arenite (SiO2 based)
sedimentary
Sandstone
Arenite
sedimentary
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
sedimentary
Red Sandstone (Iron-rich)
Ferruginous Sandstone (variable formula, primarily SiO2 + Fe2O3)
sedimentary
Concretion (Sandstone)
Carbonate-cemented Sandstone Concretion
sedimentary
Moqui Marble (Ironstone Concretion)
Iron Oxide Concretion (Fe2O3 / FeO(OH))
sedimentary
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
sedimentary