Chert
Chert (variant of microcrystalline quartz)
Category
Browse mineral on sedimentary rock specimens identified by the Rock Identifier community.
Chert
Chert (variant of microcrystalline quartz)
Quartz Geode (with Agate banding)
Silicon Dioxide (SiO2)
Jasper (likely Brecciated or Multi-colored)
Jasper (SiO2)
Agate (Grey Agate Slice)
Microcrystalline Quartz (SiO2)
Banded Agate (River Stone)
Agate (Silicon Dioxide - SiO2)
Quartz (likely Rose Quartz or Milky Quartz based on color)
Quartz (SiO2 - Silicon Dioxide)
Red Sandstone
Arenite (primarily SiO2 with hematite/iron oxide coating)
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2 - Muscovite component)
Chert
Silicon dioxide (SiO2)
Chert (potentially Flint or Mudstone)
Microcrystalline Quartz (SiO2)
Belemnoit (Fossil)
Belemnoidea (Order), Rostrum / Guard
Fossil Coral (Rugose Coral Fragment)
Rugosa (extinct order of solitary and colonial corals)
Chert (Commonly known as Flint)
Microcrystalline Quartz (SiO2)
Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)
Quartz (SiO₂)
Ironstone (likely Limonite or Goethite)
Ferruginous sedimentary rock (FeO(OH)·nH2O)
Quartzite with inclusions
Quartzite (primarily SiO2)
Granitic Sand
Detrital sediment (predominantly Quartz, Feldspar, and Mica)
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
Ironstone Concretion (Moqui Marble)
Iron Oxide Concretion (Fe2O3 / FeO(OH) mixed with SiO2)
Quartz Geode
Silicon Dioxide (SiO2) in a Geode body
Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)
Sandstone (with Iron Oxide)
Arenite with Limonite/Hematite staining
Fossilized Gastropod (Snail)
Class Gastropoda (internal mold or 'steinkern')
Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement
Gneiss
Gneiss (High-grade metamorphic rock)
Mookaite Jasper
Siliceous (chert) sedimentary rock, a form of Jasper
Quartzite / Sandstone / Chert Mix
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Chert (varietal: Flint/Jasper mix)
Hydrous Silica (SiO2)
Chert (Arrowhead)
Chert (primarily Microcrystalline Silica, SiO2)
River Cobble (Quartzite-rich Sandstone)
Clastic Sedimentary Rock (Litharenite/Quartzite transition)
River Chalcedony / Agate
Chalcedony (Silicon Dioxide, SiO2)
Agate (Chalcedony)
Cryptocrystalline Silica or Silicon Dioxide (SiO2)
Chert / River Jasper
Microcrystalline Quartz (SiO2)
Marble (Carrara style)
Recrystallized Calcite-rich Metamorphic Rock (CaCO3)
Druzy Quartz on Milky Quartz
Silicon Dioxide (SiO2)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Milky Quartz
Silicon Dioxide (SiO2)
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
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.
Gold
Native Gold (Au)
Dendritic Agate (River Pebble)
Silicon Dioxide (SiO2) with Manganese or Iron oxide inclusions