Ironstone (likely siderite or goethite-rich siltstone)
Ferruginous Siltstone
Category
Browse mineral and sedimentary specimens identified by the Rock Identifier community.
Ironstone (likely siderite or goethite-rich siltstone)
Ferruginous Siltstone
Ferruginous Breccia
Breccia with Iron-rich (Hematite/Goethite) Matrix
Tiger Iron / Banded Iron Formation
Banded Iron Formation (SiO2 with Fe2O3 and FeOOH)
Conglomerate
Conglomerate (a clastic sedimentary rock)
Orange Calcite
Calcite (Calcium Carbonate - CaCO3)
Blue Chalcedony
Microcrystalline Quartz (SiO2)
Clear Quartz Crystal Cluster
Silicon Dioxide (SiO2)
Blue Chalcedony
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Quartz
Quartz (Silicon Dioxide - SiO2)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Bauxite
Alumina-rich rock (consisting of Gibbsite, Boehmite, and Diaspore)
Quartz-veined Mudstone or Argillite
SiO2 (Quartz) in Siltstone/Mudstone matrix
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Bauxite
Hydrated Aluminum Oxides (primarily Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Diaspore α-AlO(OH))
Quartz Geode in Chert/Limestone Matrix
Silicon Dioxide (SiO2) within Sedimentary Host Rock
Chert (Iron-stained)
Chert (primarily Microcrystalline Quartz, SiO2)
Septarian Nodule or Mud Crack Fossil
Septarian Nodule (Concretion)
Chert (specifically Tan Chert)
Chert (SiO2)
Moss Agate
Agate (Silicon Dioxide, SiO2) with dendritic inclusions
Chert / River Jasper
Microcrystalline Quartz (SiO2)
Red Jasper (Chert)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Orange Calcite
Calcium Carbonate (CaCO3)
Pyrite
Iron Disulfide (FeS2)
Orange Calcite
Calcium Carbonate (CaCO3)
Pyrite
Iron Sulfide (FeS2)
Orange Calcite (Polished Sphere)
Calcium Carbonate (CaCO3)
Fluorite (likely Green Fluorite variant)
Calcium Fluoride (CaF2)
Greywacke (River Pebble)
Greywacke sandstone with quartz veining
Quartz (specifically Milky Quartz/Quartzite)
Silicon Dioxide (SiO2)
Banded Gneiss (Variety of Gneiss)
Gneiss (specifically, a variety exhibiting prominent banding; mineral composition can vary, but often contains quartz, feldspar, mica, and amphibole)
Gneiss
Gneiss
Milky Quartz
Silicon Dioxide (SiO2)
Yellow Jade (Yellow Chalcedony/Quartz)
Silicon Dioxide (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Dendritic Agate
Silicon Dioxide (SiO2) with manganese/iron inclusions
Quartz (Milky or Smoky Quartz)
Silicon Dioxide (SiO2)
Carnelian (Red Chalcedony)
Silicon Dioxide (SiO2) - variety of Chalcedony
Yellow Calcite
Calcium Carbonate (CaCO3)
Agate
Chalcedony (cryptocrystalline variety of Quartz, SiO2)
Blue Chalcedony Geode (with Quartz Druzy)
Silicon Dioxide (SiO2) - Microcrystalline variety of Quartz
Botryoidal Chalcedony (Agate)
Silicon Dioxide (SiO2)