Shale
Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)
Category
Browse organic (non rock) specimens identified by the Rock Identifier community.
Shale
Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)
Amber-bearing Coal/Sedimentary Rock
Bituminous coal or carbonaceous siltstone with Fossilized Tree Resin (C10H16O)
Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Sandstone with trace fossil
Sandstone, possibly with Skolithos or similar trace fossil
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
Agate
Silicon Dioxide (SiO2) - Banded Chalcedony
Fossiliferous Limestone
Calcite (CaCO3) Rich Bio-sedimentary Rock
Chert / Flint
Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂
Graphite
Graphite (Native Carbon, C)
Zebra Marble
Metamorphosed Alabaster/Limestone (CaCO3)
Graphite
Graphite (C)
Amber (Black)
Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)
Coral (Precious Coral)
Corallium rubrum (Red Coral), Paracorallium japonicum (Momo Coral), Pleurocorallium elatius (Sardinian Coral), various other species within the Corallidae family. Chemically, it's primarily Calcium Carbonate (CaCO 3 ).
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
Hematite
Hematite (Fe2O3)
Quartz Vein with Host Rock (Greywacke/Siltstone)
Silicon Dioxide (SiO2) within Clastic Sedimentary/Metamorphic Matrix
Chalcedony in Limestone Host Rock
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Pyrite
Iron Pyrite (FeS2)
Sandstone (with Lichen)
Arenite (primarily SiO2)
Limestone
Calcium Carbonate (CaCO3)
Quartz Geode
Silicon Dioxide (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Chert
Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)
Shale
Fissile Mudrock (Clay-rich Sedimentary Rock)
Limonite (Iron Ore/Hydrated Iron Oxide)
Limonite (mixture of FeO(OH)·nH₂O minerals, mainly Goethite, FeO(OH) and Lepidocrocite, FeO(OH))
Red Jasper
Red Jasper (variety of Chalcedony, SiO₂)
Quartz Vein on Matrix
Silicon Dioxide (SiO2)
Sandstone (Graywacke)
Clastic Sedimentary Rock (Lithic Sandstone)
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Moldavite
Silica glass with small amounts of aluminum, iron, and other elements
Conglomerate
Conglomerate (a clastic sedimentary rock)
Limestone
Calcium Carbonate (CaCO3)
Sandstone (with potential trace fossils)
Clastic sedimentary rock (primarily SiO2)
Limestone
Calcareous sedimentary rock (CaCO3)
Quartz Geode
Silicon Dioxide (SiO2) in Host Rock
Druzy Quartz on Limestone
Silicon Dioxide (SiO2)
Pumice
Pumice (Vesicular Rhyolite/Andesite)
Granite
Phaneritic plutonic rock (primarily Quartz, Feldspar, and Mica)