Quartzite River Rock (with iron staining)
Metamorphosed Sandstone (SiO2)
metamorphic
Category
Mineraloid (Human Made Geological Specimen)
Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Weathered sandstone or limestone fragment
Likely quartz-rich sandstone or calcitic limestone; exact identification is uncertain from the image
sedimentary
Small seashell fossil or shell fragment
Likely calcium-carbonate shell material, chiefly aragonite or calcite; exact species indeterminate
fossil
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Metamorphic Rock
Banded Agate
Silicon Dioxide (SiO2)
mineral
Limestone with Chert Nodule
Carbonate rock (CaCO3) with Microcrystalline Silicon Dioxide (SiO2) inclusion
sedimentary
Clear quartz crystal
Quartz (silicon dioxide, SiO₂)
mineral
Amber
Succinate (Succinite for Baltic varieties)
Organic Mineraloid
Sandstone
Arenite
sedimentary
Granodiorite
Granodiorite (Quartz + Plagioclase + Alkali Feldspar + Biotite/Hornblende)
igneous
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Iridium sand or Osmium-Iridium nugget
Iridosmine / Osmiridium (Platinoid grouping)
mineral
Gold in Quartz
Hydrothermal Quartz with Native Gold (SiO2 with Au)
mineral
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2 - Silicon Dioxide)
metamorphic
Asphalt (Bituminous Concrete)
Bituminous Concrete / Pavement
man-made (synthetic rock)
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Weathered volcanic rock, likely andesite or basalt
Fine-grained mafic to intermediate volcanic rock; probable andesite–basalt, compositionally dominated by plagioclase with pyroxene and possibly alteration minerals
igneous
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Chevron Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Fossilized coral or porous marine limestone
Likely fossil coral (Scleractinia), composed mainly of calcite/aragonite (CaCO₃)
fossil
Pegmatite
Igneous Pegmatite
igneous
Pyrite
Iron Disulfide (FeS2)
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Chert (Nodule)
Microcrystalline Quartz (SiO2)
sedimentary
Tumbled brown pebble
Indeterminate; likely quartz-rich sandstone or chert
sedimentary
Weathered agate or chalcedony nodule
Microcrystalline quartz (SiO₂), likely agate/chalcedony with iron-oxide staining
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Sunstone
Aventurine Feldspar ((Ca,Na)(Al,Si)4O8)
mineral
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Granite
Phaneritic intrusive igneous rock (approx. 70 percent SiO2)
igneous
Tumbled orange calcite
Calcite (calcium carbonate, CaCO₃)
mineral
Weathered sandstone
Quartz-rich clastic sandstone, commonly arkosic or feldspathic
sedimentary
Jasper-bearing Quartzite River Cobble
Tectonized Quartzite with Iron-Oxide (Hematite/Limonite) Veining
metamorphic
Diorite
Diorite (Plagioclase feldspar and amphibole/biotite)
igneous
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Granite Cobble
Granite (Phaneritic Quartz-Feldspar Felsic Rock)
igneous
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral