Quartz (likely) or a Quartzite Pebble
Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.
Mineral, specifically a detrital grain
Category
Mineral, Specifically A Detrital Grain
Browse mineral, specifically a detrital grain specimens identified by the Rock Identifier community.
Quartz Sand Grain
Silicon Dioxide (SiO2)
mineral
Quartz (Sand Grain size)
Silicon Dioxide (SiO2)
mineral
Garnet (likely Almandine)
Almandine Garnet, Fe3Al2(SiO4)3
mineral
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
mineral
Sandstone with Magnetite and Iron Staining
Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)
sedimentary
Mica (likely Muscovite)
Muscovite / KAl2(AlSi3O10)(OH)2
mineral
Conglomerate
Conglomerate (Detrital sedimentary rock)
sedimentary
Conglomerate
Conglomerate (Detrital sedimentary rock)
sedimentary
Granite Pegmatite with Tourmaline and Muscovite
Pegmatite (Feldspar: KAlSi3O8, Quartz: SiO2, Schorl: NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH))
igneous
Mahogany Obsidian Arrowhead
Obsidian (volcanic glass) with Hematite inclusions
igneous
Turquoise and Red Coral (with Grizzly Bear Claw)
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Precious Coral (Corallium rubrum)
mineral
Almandine Garnet
Almandine (Fe3Al2Si3O12)
mineral
Sandstone (Pebble)
Sandstone (arenite, arkose, wacke depending on composition)
sedimentary
Basalt with Vesicle/Vug
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Garnet (Almandine/Pyrope variety)
Silicate mineral group; typically Fe3Al2(SiO4)3 (Almandine) or Mg3Al2(SiO4)3 (Pyrope)
mineral
Sandstone (Ferruginous)
Arenite (Fe-rich)
sedimentary
Conglomerate
Conglomerate (Detrital sedimentary rock)
sedimentary
Granite
Granite (Felsic Plutonic Rock)
igneous
Granite (specifically the Ubatuba variety)
Phaneritic Igneous Rock (Granodiorite/Monzogranite)
igneous
Mixed collection of minerals and rocks (Jasper, Carnelian, Granite, and Quartz)
Silicon Dioxide (SiO2) with varying impurities for silicates and igneous aggregates
igneous, sedimentary, and metamorphic
Basalt with Epidote Veins
Mafic Igneous Rock (Basalt)
igneous
Glauconitic Sandstone
Glauconitic Quartz-Wacke / Sandstone (Fe(II),Fe(III),Al,Mg)2-3(Si,Al)4O10(OH)2
sedimentary
Dalmatian Stone
Peralkaline Feldsphathic Igneous Rock
igneous
Conglomerate
Conglomerate (Detrital sedimentary rock)
sedimentary
Unidentifiable Rock Fragment
Uncertain
River/Stream Pebble
Clast / Detrital Grain / Rounded Sedimentary Particle (Compositionally variable, commonly Quartz, Feldspar, Chert, or other resistant rock fragments)
Mineral, specifically a rock fragment
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Conglomerate
Conglomerate (Detrital Sedimentary Rock)
sedimentary
Schorl (Black Tourmaline)
Sodium Iron Aluminum Borosilicate (NaFe3Al6(BO3)3Si6O18(OH)4)
mineral
Chert (specifically Tan Chert)
Chert (SiO2)
sedimentary
Black Tourmaline (Schorl)
Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3(OH)4)
Mineral
Granitic Sand
Detrital sediment (predominantly Quartz, Feldspar, and Mica)
sedimentary
Granitic Pegmatite
Granite Pegmatite (coarse-grained intrusive igneous rock)
igneous
Glauconitic Sandstone (Greensand)
Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
sedimentary
Ironstone Concretion (Moqui Marble)
Iron-oxide Concretion (Hydrated ferric oxide, Fe2O3·nH2O)
sedimentary
Yellow Jasper / Chert
Silicon Dioxide (SiO2) with Goethite or Limonite inclusions
sedimentary
Quartz
Silicon Dioxide (SiO2)
Mineral
Amber (Burmite)
Fossilized tree resin (Succinite variant)
Organic mineraloid
Agate (specifically Carnelian or Honey Agate)
Silicon Dioxide (SiO2)
Mineral
Brown Antique Granite
Anorthosite (Technically a plutonic rock composed mainly of plagioclase feldspar)
igneous
Diabase
Diabase (also known as Dolerite)
igneous