Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
Category
Browse sedimentary or metamorphic (low grade) specimens identified by the Rock Identifier community.
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
Yellow Chalcedony (Agate Pebble)
Silicon Dioxide (SiO2)
Dragon Stone (Septarian Nodule/Concretion)
Septarian Concretion (Composition: Calcite, Aragonite, Limestone/Clay)
Jasper and Quartz conglomerate (River Rock)
Silicon Dioxide (SiO2) - Chalcedony and Quartz variety
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))
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Banded Iron Formation (BIF)
Banded Iron Formation (SiO2 + Fe2O3/Fe3O4)
Chert (specifically Yellow or Brown Chert / Jasper)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
White Chalcedony (likely Common Opal or Milky Quartz)
Silicon Dioxide (SiO2)
Quartz Geode
Clear Quartz (Silicon Dioxide, SiO2)
Carnelian Agate
Silicon Dioxide (SiO2) with iron oxide impurities
Pyrite
Iron Sulfide (FeS2)
Chert (Arrowhead/Tool Grade)
Microcrystalline Quartz (SiO2)
Almandine Garnet
Almandine (Fe3Al2Si3O12)
Pyrite
Iron Pyrite (FeS₂)
Charoite
Charoite (Hydrated silicate of potassium, sodium, calcium, barium and strontium): (K,Sr,Ba)(Na,Ca)2[Si4O10](OH,f)·H2O
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Muscovite Schist with Quartz
Mica Schist (KAl2(AlSi3O10)(OH)2)
Rhodonite (in matrix)
Rhodonite (Mn,Fe,Mg,Ca)SiO3
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Chert (Lightly weathered variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Specular Hematite with Quartz and Limonite
Hematite (Fe2O3) with Quartz (SiO2) and Limonite (FeO(OH)·nH2O)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
Pyrite
Iron Disulfide (FeS2)
Magnetite
Iron(II,III) oxide (Fe3O4)
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
Banded Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Fluorite (Green Fluorite)
Calcium Fluoride (CaF2)
Lapis Lazuli
Complex mixture of minerals (lazurite, calcite, pyrite, and sodalite); (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2
Jasper
Silicon dioxide (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Chert (specifically Yellow/Common Opal or Jasper mixture)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Chert (often called Flint or Jasper based on color)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Septarian Nodule (Septarian Dragon Stone)
Septarian Concretion (CaCO3 + Al2Si2O5(OH)4)