Weathered iron-rich sandstone or ferruginous siltstone
Clastic sedimentary rock, likely quartz-rich sandstone cemented by iron oxides (Fe₂O₃/Fe₃O₄)
sedimentary
Category
Man Made Composite (Lithified Equivalent Of Sedimentary)
Browse man made composite (lithified equivalent of sedimentary) specimens identified by the Rock Identifier community.
Learn about Man Made Composite (Lithified Equivalent Of Sedimentary) in the encyclopedia
View all →
Quartz (likely macrocrystalline variety)
Quartz (SiO₂)
Mineral
Quartz
Silicon Dioxide (SiO2)
Mineral
Slate
Slate (a fine-grained, foliated metamorphic rock). Mineral composition: Primarily composed of mica minerals (muscovite, chlorite, sericite) and quartz, with minor amounts of hematite, pyrite, and other accessory minerals.
sedimentary
Milky Quartz
Quartz (SiO2)
Mineral
Granite (Pegmatitic)
Phaneritic Felsic Igneous Rock
igneous
Schist
N/A (a rock type, not a mineral formula)
metamorphic
Sandstone (Water-worn Pebble)
Clastic Sedimentary Rock (primarily Quartz and Feldspar)
sedimentary
Quartz
Silicon Dioxide (SiO2)
Mineral
Dumortierite in Quartz
Dumortierite (Al6O3(BO3)(SiO4)3) with Quartz (SiO2)
mineral
Diamond
Carbon (C)
gemstone
Rounded brown pebble, likely weathered sandstone or iron-stained quartzite
Probable quartz-rich sandstone (SiO₂-dominated); exact identification requires testing
sedimentary
Pallasite Meteorite
Pallasite (Stony-Iron Meteorite)
meteorite
Diamond
Carbon (C)
gemstone
Quartzite
Quartzite (SiO2)
metamorphic
Banded Gneiss
Gneiss (variable mineral composition)
metamorphic
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
mineral
Oolitic Limestone
Oolite (Sedimentary rock composed of CaCO3)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite (primarily Quartz-rich)
sedimentary
Dalmatian Stone (commonly Dyed)
Dalmatian Jasper (Peralkaline igneous rock)
igneous
Dalmatian Jasper
Peralkaline Quartz-Feldspar Rock with Arfvedsonite
igneous
K2 Jasper (K2 Granite)
Granite with Azurite inclusions (SiO2 + Cu3(CO3)2(OH)2)
igneous
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
sedimentary
Quartz
Quartz (SiO₂)
Mineral
Pebble (river rock/beach pebble)
Pebble (clast size class)
Sedimentary Rock
Raw Diamond
Carbon (C)
gemstone
Diamond (in jewelry setting)
Adamantine Carbon (C)
mineral
Diamond (Faceted)
Carbon (C)
gemstone
Feldspar-rich Pegmatite
Granitic Pegmatite (principally KAlSi3O8)
igneous
Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Mixed collection of common river stones
Varied lithologies, visibly including quartz-rich rock, dark mafic rock, sandstone, and purple quartz-bearing material
igneous, sedimentary, metamorphic
Emerald (Rough)
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
mineral
Tumbled chalcedony (likely blue-gray agate)
Cryptocrystalline quartz, SiO₂; chalcedony/agate variety
mineral
Tourmaline-bearing pegmatite
Quartz–feldspar pegmatite with black schorl tourmaline; minor mica likely present
igneous
Sandstone
Arenite
sedimentary
Weathered brown stone, possibly basalt or iron-rich sedimentary rock
Indeterminate from photograph; likely fine-grained mafic rock (basalt) or ferruginous sandstone
igneous
Fossilized shell fragment
Indeterminate fossil mollusk; likely a silicified or mineral-replaced bivalve/gastropod fragment
fossil
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Blue chalcedony cabochon (probable)
Chalcedony, cryptocrystalline quartz; silicon dioxide (SiO₂)
gemstone
Fancy Jasper
Chalcedony (cryptocrystalline quartz) with inclusions
Mineral
Diamond
C (Native Carbon)
gemstone