Fossilized Coral
Anthozoa (Fossilized)
Category
Browse metamorphic or sedimentary depending on local grade specimens identified by the Rock Identifier community.
Fossilized Coral
Anthozoa (Fossilized)
Ferruginous Sandstone (Gritstone)
Clastic sedimentary rock with iron-rich cement (FeO(OH)·nH2O)
Nephrite Jade
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)
Quartz (milky quartz variety)
Quartz (SiO₂)
Sunstone
Plagioclase Feldspar (specifically Oligoclase variety containing hematite or goethite inclusions)", composition: (Ca,Na)(Al,Si)2Si2O8
Sunstone and Green Aventurine
Sunstone: (Ca,Na)[(Al,Si)2Si2O8] (Plagioclase Feldspar Group); Green Aventurine: SiO2 (Quartz)
Sapphire
Corundum (Al₂O₃) with trace elements causing color variations.
Limonite (Hydrated Iron Oxide / Bog Iron)
FeO(OH)·nH2O
Cardstock (Paper)
Cellulose (C6H10O5)n
Green Aventurine
Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Marble (White)
Metamorphosed Limestone (mainly CaCO3)
Magnetite Orthorthotropic Rock
Magnetite (Fe3O4)
Banded Iron Formation (BIF)
Banded Iron Formation (predominantly Hematite, Magnetite, and Chert/Quartz)
Limestone (Cliff Formation)
Limestone (predominantly CaCO3 as calcite)
Almandine Garnet
Almandite (Fe3Al2(SiO4)3)
Chert (Field-collected variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Ferruginous Sandstone (Gozzan/Ironstone)
Arenite with Limonite/Goethite cement (FeO(OH)·nH2O)
Siderite Concretion (Nodule)
Iron Carbonate (FeCO3) Concretion
Ferruginous Sandstone (Ironstone)
Clastic sedimentary rock (SiO2 with Fe2O3/FeO(OH) cement)
Ironstone (Limonitic Shale)
Ferruginous Siltstone / Goethite-rich Sedimentary Rock
Druzy Quartz (on Quartzite or Chert)
Silicon Dioxide (SiO2)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminium phosphate)
Muscovite Schist with Quartz
KAl2(AlSi3O10)(OH)2 in Schistose matrix
Tiger's Iron
Pseudomorphic Quartz Aggregate (contains SiO2 with Fe2O3 and FeOOH)
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Jasper)
Limestone (Micrite/Chalky variety)
Calcium Carbonate (CaCO3)
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
Yellow Chalcedony (Agate Pebble)
Silicon Dioxide (SiO2)
Jasper and Quartz conglomerate (River Rock)
Silicon Dioxide (SiO2) - Chalcedony and Quartz variety
Crushed Limestone (Gravel)
Calcium Carbonate (CaCO3)
Dragon Stone (Septarian Nodule/Concretion)
Septarian Concretion (Composition: Calcite, Aragonite, Limestone/Clay)
Chert (Jasper variety)
Silicon Dioxide (SiO2) with iron oxide impurities
Bauxite
Bauxite (Mixture including Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Diaspore α-AlO(OH))
Banded Iron Formation (BIF)
Banded Iron Formation (SiO2 + Fe2O3/Fe3O4)
Chert (specifically Yellow or Brown Chert / Jasper)
Silicon Dioxide (SiO2)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Sandstone (specifically Flagstone)
Arenite (primarily composed of SiO2)
Ocean Jasper
Orbicular Jasper (Silicon Dioxide SiO2)
Red Sandstone
Arenite (with Iron Oxide / Hematite cementation)
Puddingstone
Conglomerate
Shale
Shale (comprised mostly of clay minerals and quartz)
Quartz (Smoky/Grey variety)
Silicon Dioxide (SiO2)