River Rocks and Pebbles
Mixed Silica-rich Sediments (SiO2 based)
sedimentary
Category
Sedimentary Rock (Possibly Composed Of Various Minerals)
Browse sedimentary rock (possibly composed of various minerals) specimens identified by the Rock Identifier community.
Learn about Sedimentary Rock (Possibly Composed Of Various Minerals) in the encyclopedia
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Granite
Granite
Igneous
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals, e.g., Lizardite, Chrysotile, Antigorite)
metamorphic
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals like Antigorite, Lizardite, and Chrysotile)
metamorphic
Basalt
Basalt (primarily composed of Plagioclase Feldspar and Pyroxene)
igneous
Quartz (Gravel fragment)
Quartz (Silicon Dioxide, SiO2)
mineral
Granite
Phaneritic plutonic rock (Quartz, Alkali Feldspar, and Plagioclase)
igneous
Ironstone concretion
Siderite or Limonite-rich Concretion (FeO(OH)·nH2O)
sedimentary
Gemstone Ring
Various (Likely Glass, Cubic Zirconia, or assorted semi-precious stones)
gemstone
Calcite
Calcite (Mineral; CaCO₃)
Mineral
Marble
Marble (metamorphosed limestone or dolostone), primarily composed of calcite (CaCO3) or dolomite (CaMg(CO3)2)
metamorphic
Rounded granitic cobble
Granite, likely biotite granite or granodiorite
igneous
Shale fragment
Shale (clay mineral rich sedimentary rock)
sedimentary
Granite
Plutonic Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Septarian Nodule (Sphere)
Septarian (composed of Calcite, Aragonite, and Limestone/Claystone)
sedimentary
Granite
Phaneritic Plutonic Igneous Rock (primarily composed of quartz, alkali feldspar, and plagioclase)
igneous
Generic Rock / Pebble
Undetermined rock specimen
sedimentary
Chert (Nodule)
Chert (composed of Microcrystalline Silica/SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Sandstone
SiO2 (predominantly quartz sand)
sedimentary
Sandstone (likely Arkosic or Quartzose)
Sandstone (SiO2 with inclusions)
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Jade (Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)
Mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Banded gneiss pebble
Foliated gneiss, typically quartz–feldspar–mica bearing
metamorphic
Dalmatian Stone
Dalmatian Jasper (Aplitic Perthite)
igneous
Granite Cobble
Granite (Phaneritic igneous rock)
igneous
Limestone (Micritic)
Sedimentary rock mainly composed of Calcium Carbonate (CaCO3)
sedimentary
Chert / Microcrystalline Quartz
Silicon Dioxide (SiO2)
sedimentary
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Granite
Intrusive Igneous Rock
igneous
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Fossiliferous Limestone
Biogenic Sedimentary Rock (CaCO3)
sedimentary
Granite
Phaneritic Felsic Igneous Rock (Main minerals: SiO2, KAlSi3O8, NaAlSi3O8)
igneous
Mammoth or Mastodon Tooth Fragment
Mammuthus / Mammut molar fragment
fossil
Dalmatian Jasper
Peralkaline Rhyolite (composed of Quartz, Feldspar, and Arfvedsonite)
igneous
Serpentinite
Serpentinite (composed primarily of Serpentine minerals: Mg3Si2O5(OH)4)
metamorphic
Greenstone / Serpentinite
Serpentinite (composed primarily of serpentine minerals: Mg3Si2O5(OH)4)
metamorphic
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Vesicular Basalt (commonly mistaken for Slag)
Scoriaceous Basalt (composed primarily of Plagioclase Feldspar and Pyroxene)
igneous
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)
igneous
Pyrite with quartz
Pyrite (FeS₂) with quartz (SiO₂), possibly minor chalcopyrite
mineral