Sandstone
Arenite (SiO2 principal)
sedimentary
Category
Synthetic Material (Not A Rock Or Mineral)
Browse synthetic material (not a rock or mineral) specimens identified by the Rock Identifier community.
Learn about Synthetic Material (Not A Rock Or Mineral) in the encyclopedia
View all →
Sandstone
Arenite (SiO2 principal)
sedimentary
Concrete
Anthropogenic Conglomerate
sedimentary
Sandstone
Sedimentary Rock (Quartzose Sandstone)
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Weathered granite or granitic gneiss
Granite/granitic gneiss, composed mainly of quartz, feldspar, and mica
igneous
Uncertain pale green-gray mineral/rock fragment
Possibly serpentine-bearing rock or greenstone; exact identification requires testing
mineral
Sandstone
Arenite
sedimentary
Sandstone
Arenite
sedimentary
Fossil Snail
Gastropoda (fossilized)
fossil
Blue Goldstone
Aventurine glass (Synthetic borosilicate glass with cobalt and metallic inclusions)
man-made glass
Mica-rich schist (likely muscovite schist)
Muscovite–quartz schist; chiefly muscovite mica, quartz, and minor feldspar/biotite
metamorphic
Sandstone
Sandstone (composed predominantly of SiO2)
sedimentary
Likely weathered granite or granitic gneiss
Granite: quartz + feldspar + mica; possibly gneiss if the faint texture reflects foliation
igneous
Sandstone
Sedimentary Rock (Quartz arenite or arkose)
sedimentary
Dark igneous rock, likely basalt or diabase, with a second purplish specimen
Basalt/diabase; exact identification is uncertain from the photograph
igneous
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
sedimentary
Sandstone Pebble
Sedimentary Rock (Quartzose Sandstone)
sedimentary
Serpentinite (likely veined variety)
Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and carbonate veins
metamorphic
Gravel / Limestone Fragment
Calcium Carbonate (CaCO3) / Fine-grained Sedimentary Rock
sedimentary
Ruby (Faceted)
Corundum (Al2O3:Cr)
gemstone
Blue-green copper mineral specimen, likely chrysocolla with malachite and quartz
Chrysocolla (hydrated copper aluminum silicate; approximate formula (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O), possibly mixed with malachite (Cu₂CO₃(OH)₂) and quartz
mineral
Dark, iron-stained rock; exact identification uncertain
Possibly a fine-grained mafic igneous rock (basalt or diabase); image alone is insufficient for a reliable species-level identification
igneous
Sandstone
Arenite (SiO2 based)
sedimentary
Fire Opal (in matrix)
Hydrated Silica (SiO2·nH2O)
Mineraloid
Sandstone (lithic/quartz variant)
Clastic sedimentary rock (SiO2 predominant)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone (lithic wacke/conglomerate mix)
Clastic Sedimentary Rock (SiO2 with lithic fragments)
sedimentary
Sandstone
Arenite (SiO2 primarily)
sedimentary
Sandstone (Tumbled / Rounded)
Sedimentary Rock (Quartz arenite)
sedimentary
Small dark mineral/rock fragment
Indeterminate; possibly biotite-rich schist, graphite, or metallic sulfide
mineral
Shale
Laminated Mudstone
sedimentary
Sandstone
Arenite
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Sandstone
Arenite (SiO2 based)
sedimentary
Sandstone with Quarzite clasts
Arenite (SiO2 based)
sedimentary
Sandstone (Ferruginous)
Arenite with Iron Oxide matrix
sedimentary
Sandstone
Clastic sedimentary rock
sedimentary
Tumbled orange-and-white chalcedony/agate
Microcrystalline quartz (SiO₂), likely iron-stained chalcedony or carnelian-bearing agate
mineral
Sandstone
Sedimentary Rock (Quartz arenite or arkose)
sedimentary