Chert / Fossiliferous Limestone
Sedimentary Chert (often containing CaCO3 or SiO2 replacements)
sedimentary
Category
Marble
Browse marble specimens identified by the Rock Identifier community.
Olivine (Peridot)
Magnesium Iron Silicate ((Mg, Fe)2SiO4)
mineral
Fossiliferous Limestone
Biogenic Limestone (CaCO3)
sedimentary
Limestone with Chert
Calcium Carbonate (CaCO3) with Silica (SiO2) inclusions
sedimentary
Chert (River Siltstone/Quartzite)
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Glauconitic Sandstone
Greensand (Glauconite-bearing sandstone)
sedimentary
Glauconitic Sandstone
Glauconitic Quartz Arenite
sedimentary
Crinoidal Limestone
Bioclastic Limestone
Sedimentary
Olivine in Basalt matrix
Peridotite (Mg, Fe)2SiO4
igneous
Black Pearl (Tahitian or Irradiated Type)
Organic gemstone (Calcium Carbonate with Conchiolin Binding)
mineraloid
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Peridotite (with Olivine)
Peridotite (dominantly (Mg, Fe)2SiO4)
igneous
Olivine (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4
mineral
Olivine (Peridot when gem-quality)
Olivine Group (Magnesium Iron Silicate, (Mg,Fe)2SiO4)
mineral
Glauconitic Sandstone
Glauconitic sandstone ((K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Peridotite
Peridotite (primarily Olivine and Pyroxene)
igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Microcrystalline Limestone Pebble
Carbonate sedimentary rock (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Natural White Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin - CaCO3
mineraloid
Peridotite (Pyroxenite/Serpentinized Dunite)
Ultramafic Rock (consisting primarily of Olivine and Pyroxene)
igneous
Pearl (in a decorative hair comb setting)
Calcium carbonate (CaCO3) primarily as Aragonite, bonded with Conchiolin
Organic Mineraloid
Chert (Beach Pebble)
Silicon Dioxide (SiO2)
sedimentary
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
mineral
Fossiliferous Limestone
Calcium Carbonate - CaCO3
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Peridotite
Peridotite (composed largely of Olivine (Mg,Fe)2SiO4)
igneous
Olivine Diabase Porphyry
Porphyritic Olivine-Bearing Diabase (Micro-Gabbro)
igneous
Granitoid
Granitoid (comprising Quartz, Feldspar, and Mica/Amphiboles)
igneous
Limestone with Calcite Veins
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)
sedimentary
Olivine (Peridot)
Magnesium Iron Silicate ((Mg, Fe)2SiO4)
mineral
Olivine
(Mg, Fe)2SiO4
Mineral
Fossiliferous Limestone
Biogenic Limestone with Brachiopod/Crinoid fragments
sedimentary
Glauconite (Sandstone or Shale)
Glauconite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
sedimentary
Olivine (Peridotite)
Magnesium iron silicate ((Mg, Fe)2SiO4)
igneous
Crushed Limestone
Calcium Carbonate (CaCO3)
sedimentary
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
mineral
Ferruginous Sandstone
Arenite with Iron Oxide cement (Fe2O3 / FeO(OH))
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Glauconitic Sandstone
Glauconitic Sandstone (complex silicate formula: (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary