Sandstone Concretion
Clastic sedimentary rock (primarily Quartz SiO2)
sedimentary
Category
Sedimentary Rock (Possibly Composed Of Various Minerals)
Browse sedimentary rock (possibly composed of various minerals) specimens identified by the Rock Identifier community.
Painted River Pebble (likely Basalt or Greywacke)
Aphanitic Lithic Clast with Anthropogenic Pigment coating
Sedimentary or Igneous
Sandstone (Quartzite-rich River Cobble)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Quartz / Limestone Gravel
SiO2 (Silicon Dioxide) and CaCO3 (Calcium Carbonate)
igneous and sedimentary mixture
Quartzite
Quartzite (SiO2)
metamorphic
Greywacke (River Pebble with Quartz Veins)
Greywacke (Indurated Sandstone); Veins: SiO2 (Quartz)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Calcite Geode
Calcium Carbonate (CaCO3)
mineral
Banded Iron Formation
Banded Iron Formation (BIF)
Sedimentary Rock
Sandstone
Arenite
sedimentary
Tree Agate (also known as Dendritic Agate)
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
mineral
Hypersthene
Hypersthene ((Mg,Fe)SiO₃)
Mineral
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Ferruginous Oxides
mineral
Chalcedony (Agate/Quartz)
Silicon Dioxide (SiO2)
mineral
Sandstone (Quartzose type)
Arenite (primarily SiO2)
sedimentary
Sandstone (Water-worn)
Arenite
sedimentary
Amygdaloidal Basalt
Amygdaloidal Mafic Volcanic Rock (Basalt)
igneous
Ferruginous Sandstone (Ironstone Nodules)
Ferruginous Sandstone with Limonite/Goethite coating (Fe2O3·H2O)
sedimentary
Conglomerate
Conglomerate (SiO2 matrix with various inclusions)
sedimentary
Yellow Aventurine
Quartz (SiO2) with iron-bearing inclusions
mineral
Sandstone (Ferruginous)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
sedimentary
Agate (or Chalcedony)
Silicon Dioxide (SiO2)
mineral
Sandstone (Quartz Sandstone)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Garnet Schist
Garnetiferous Micaceous Schist
metamorphic
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
mineral
Blue Quartz (Aventurine)
Silicon Dioxide (SiO2) with inclusions of crocidolite or dumortierite
mineral
Nacre (Mother of Pearl)
Nacre (Biogenic Aragonite/Calcite composite, CaCO3)
mineral
Granite Sand (Decomposed Granite)
Grus / Quartz-Feldspar Detritus
sedimentary
Granite
Granite (Felsic Plutonic Rock)
igneous
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock)
igneous
Mica Schist
Mica Schist (primarily Muscovite or Biotite KAl2(AlSi3O10)(OH)2)
metamorphic
Slate
Slate (foliated metamorphic rock)
metamorphic
Diamond
Diamond (C)
mineral
Pumice
Pumicite (fine-grained pumice), Scoria (similar origin but denser and darker, usually basaltic)
Igneous
Sandstone
Clastic sedimentary rock (Quartz arenite/Arkose)
sedimentary
River Stone (Granitic Gneiss)
Foliated Granitic Gneiss
metamorphic
Sandstone
Arenite (predominantly SiO2)
sedimentary
Mexican Crazy Lace Agate
Silicon Dioxide (SiO2) with iron and aluminum inclusions
mineral
Quartz (Druzy or Geode fragment)
Silicon Dioxide (SiO2)
mineral
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily Quartz with Limonite/Goethite staining)
sedimentary
Sandstone (Micaceous)
Arenite (primarily SiO2 with Phyllosilicates)
sedimentary
Clay Brick
Ceramic structural unit (Al2O3·2SiO2·2H2O as precursor)
metamorphic (man-made/anthropogenic)