Fossilized Horn Coral
Rugosa
Category
Browse mineral and sedimentary specimens identified by the Rock Identifier community.
Fossilized Horn Coral
Rugosa
Almandine Garnet in Schist
Almandine, Fe3Al2(SiO4)3
Red Sandstone
Arenite with Hematite cementation
Septarian Nodule (Dragon Stone)
Septarian (composed of Calcite CaCO3, Aragonite CaCO3, and Limestone/Clay)
Petrified Wood
Silicified Wood (SiO2)
Orthoceras Fossil in Limestone
Orthoceras (extinct genus of cephalopods) in Carboniferous or Devonian Limestone
Jasper (specifically Red Jasper/Chert)
Silicon Dioxide (SiO2) with iron oxide inclusions
Jasper (Red Jasper)
Jasper (SiO2 - Silicon Dioxide with iron inclusions)
Jasper
Jasper (Silicon Dioxide, SiO2 with iron inclusions)
Chert (Jasper/Limonitic Chert)
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Iron inclusions
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Gneiss (specifically a Banded Gneiss pebble)
Gneiss (High-grade Regional Metamorphic Rock)
Gneiss with Quartz Veining
Gneiss (High-grade regional metamorphic rock)
Chert (Brown variety / Common Jasper)
Microcrystalline Quartz (SiO2)
Rough Emerald (Beryl)
Emerald (Be3Al2(SiO3)6 with Cr/V impurities)
Schist
N/A (a rock type, not a mineral formula)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Jasper
Silicon Dioxide (SiO2) with impurities
Chert (specifically Flint or Common Chert node)
Silicon Dioxide (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Ironstone Nodule (Ironstone Concretion)
Siderite-rich Mudstone (FeCO3) or Limonite (FeO(OH)·nH2O)
Sulfur
Native Sulfur (S8)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Jasper (Iron Oxide Rich)
Silicon Dioxide (SiO2) with Fe2O3 (Hematite/Goethite) inclusions
Quartz Geode
Silicon Dioxide (SiO2)
Red Sandstone (Iron-rich)
Ferruginous Sandstone (variable formula, primarily SiO2 + Fe2O3)
Chert (Flint) with Glauconite
Microcrystalline Quartz (SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Pink Rhodonite
Manganese Silicate (MnSiO3)
Pyrite
Iron Disulfide (FeS2)
Fluorite
Calcium Fluoride (CaF2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Quartz Geode
Silicon Dioxide (SiO₂)
Fluorite (Rainbow Fluorite)
Calcium Fluoride (CaF2)
Green Calcite (often commercially called Green Onyx)
Calcium Carbonate (CaCO3)
Red Jasper (Opaque Chalcedony)
Jasper / Silicon Dioxide (SiO2) with Ferric Iron inclusions
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Jasper Agate
Chalcedony (Silicon Dioxide - SiO2)
Green Calcite
Calcite (Calcium Carbonate, CaCO3)
Quartz (specifically Milky/White Quartz)
Silicon Dioxide (SiO2)