Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Category
Browse igneous or sedimentary (water worn) specimens identified by the Rock Identifier community.
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Chert / Flint
Cryptocrystalline Quartz (SiO2)
Blue Chalcedony
Chalcedony (cryptocrystalline Silicon Dioxide - SiO2)
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Turquoise (Rough)
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Jasper and Quartz River Cobble
Silicon Dioxide (SiO2) with Hematite inclusions
Fancy Jasper
Silicon Dioxide (SiO₂)
Hag Stone
Perforated Sandstone (composed of SiO2 and calcareous cement)
Sandstone (Yellow/Tan Sandstone)
Arenite (primarily Quartz, SiO2)
Limestone
Calcium Carbonate (CaCO3)
Sandstone
Arenite (SiO2 based)
Pumice
Pumice (Vesicular Rhyolite/Dacite)
Scoria
Vesicular Basalt / Scoria
Scoria
Vesicular Basaltic Andesite/Scoria
Scoria (Lava Rock)
Mafic extrusive volcanic rock (Scientific formula varies based on mineral content: primarily SiO2, MgO, and FeO)
Ferruginous Siltstone or Mudstone
Ferruginous Siltstone / Goethitic Sandstone
Conglomerate
Conglomerate (clastic sedimentary rock)
Pyrite
Iron Sulfide (FeS2)
Brecciated stone pebble
Breccia
River Gravel (Quartzite and Chert pebbles)
Silicon Dioxide (SiO2)
Chert
Chert (SiO2)
Pebble (likely Quartz or Chert)
SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.
Dendrite (Manganese Oxide Dendrites)
Psilomelane or Pyrolusite on Matrix (typically MnO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Granite (Pink Orthoclase variety)
Phaneritic intrusive igneous rock (Quartz, Orthoclase, Plagioclase, and Mica)
Limestone (specifically Tufa or Travertine)
Calcium Carbonate (CaCO3)
Ironstone Concretion (Moqui Marble)
Iron Oxide Concretion (Fe2O3 / FeO(OH) mixed with SiO2)
Basalt Beach Pebble
Basalt (Aphanitic Mafic Volcanic Rock)
Rhyolite Pebble
Rhyolite
Granite Pebble
Granite (composition of Quartz, Alkali Feldspar, and Plagioclase)
Basalt (River Stone)
Basalt
Granitic Pegmatite
Granitic Pegmatite (principally Quartz, Feldspar, and Mica)
Sandstone
Arenite (SiO2 based)
Granite (Weathered)
Course-grained Intrusive Igneous Rock
Conglomerate
Conglomerate (clastic sedimentary rock type)
Magnetite
Magnetite (Iron(II,III) oxide, Fe3O4)
Conglomerate
Conglomerate (clastic sedimentary rock)
Conglomerate
Conglomerate (clastic sedimentary rock)
Dalmatian Stone
Peralkaline rhyolite
Sandstone
Arenite (SiO2 based)