Gneiss
Foliated Metamorphic Rock
Category
Browse sedimentary or metamorphic (base substrate) specimens identified by the Rock Identifier community.
Gneiss
Foliated Metamorphic Rock
Coquina or Fossiliferous Conglomerate
Bioclastic Rudstone (variable composition)
Gastropod Steinkern (Fossil Snail Internal Mold)
Class Gastropoda (Internal Mold)
Sandstone
Arenite (Sedimentary rock composed of sand-sized grains)
Hag Stone
Porous sedimentary rock (typically Flint, Chert, or Sandstone) with naturally occurring holes
Sandstone
Arenite (composed primarily of Quartz: SiO2)
Milky Quartz in Matrix
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Banded gneiss (likely amphibolite-bearing gneiss)
Gneiss; quartz–feldspar–mica/amphibole aggregate
River Quartzite Siltstone
Quartz-rich Meta-siltstone (SiO2 dominated)
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Limestone
Calcareous Sedimentary Rock (CaCO3)
Sandstone
Arenite (predominantly SiO2 quartz grains)
Sandstone (Cross-bedded Drill Core)
Clastic Sedimentary Rock (primarily SiO2)
Pink Rhodonite
Manganese Silicate (MnSiO3)
Epidote
Epidote Group (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
Brown Chert
Cryptocrystalline Silica (SiO2)
Limonite Stained Basalt
Hydrated Iron Oxide on Mafic Volcanic Rock (FeO(OH)·nH2O)
Sandstone
Arenite
Fossilized Shark Tooth
Chondrichthyes (Class)
Limestone with Weathering Rind
Calcium Carbonate (CaCO3) - Bioclastic or Micritic Limestone
Limestone
Calcium Carbonate (CaCO3)
Chert (Pebble)
Microcrystalline Quartz (SiO2)
Chert (River Pebble)
Silicon Dioxide (SiO2)
Greywacke with Quartz Veins
Lithic Wacke (SiO2 enriched)
Chert / Flint
Silicon Dioxide (SiO2)
Graywacke Pebble (River Stone)
Graywacke (Lithic wacke)
Chert (Flint Nodules)
Chert (Cryptocrystalline variety of Quartz, SiO2)
Chert Nodule (Commonly known as a Flint or River Cobble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Greywacke
Lithic Sandstone (Greywacke)
Ironstone Concretion
Ironstone (primarily Siderite or Limonite / Goethite, FeO(OH)·nH2O)
Banded Chert
Microcrystalline Quartz (SiO2)
Coquina / Shelly Limestone
Coquina (calcium carbonate, CaCO3)
Fossiliferous Limestone (Chertified Limestone)
Calcium Carbonate (CaCO3) often replaced by Microcrystalline Silica (SiO2)
Conglomerate (River Rock Aggregate)
Conglomerate (Lithic-clast conglomerate)
Chert (Basanite variety) with Quartz Vein
Microcrystalline Quartz (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Chert (and associated Flint)
Silicon Dioxide (SiO2)
Chert (Iron-rich or Jasperoid)
Cryptocrystalline Quartz (SiO2)
Chert (variations include Chalcedony and Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Brecciated River Cobble)
Silicon Dioxide (SiO2)
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)