Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Category
Browse limestone specimens identified by the Rock Identifier community.
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Chert Nodules / Flint
Chert (Silicon Dioxide, SiO2)
Lapis Lazuli
Lapis Lazuli (A metamorphic rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, along with Calcite and Pyrite)
Yellow Calcite
Calcium Carbonate (CaCO3)
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Rhodochrosite
Manganese Carbonate (MnCO3)
Marble
Recrystallized Calcite (CaCO3)
Chert (varietal: Jasper or Ironstone nodule)
Microcrystalline Quartz (SiO2) with iron oxides
Leland Blue Stone
Anthropogenic Iron Smelting Slag
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
Fossilized Brain Coral
Diploria labyrinthiformis (Fossilized)
Ferruginous Slag (Iron Smelting Byproduct)
Fused Silicate Scoria (Amorphous mixture of FeO, SiO2, and CaO)
Chert (specifically Tan/Yellow Chert)
Silicon Dioxide (SiO2)
Marble (Carrara style)
Recrystallized Calcite-rich Metamorphic Rock (CaCO3)
Lapis Lazuli
Lapis lazuli (primary component: Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
Chert (Jasper/Flint Pebble)
Microcrystalline quartz (SiO2)
Epidote
Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))
Flint Nodule
Microcrystalline Quartz (SiO2)
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
Banded Calcite (often sold as Mexican Onyx or Aragonite)
Calcite/Aragonite (Calcium Carbonate, CaCO3)
River Pebbles (Stream-rounded rocks)
Fluvial Detritus (varied mineralogy)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Common Opal/Agate inclusion)
Microcrystalline Quartz (SiO2)
Travertine
Travertine (CaCO3 - Calcium Carbonate)
Lapis Lazuli
Complex mixture of minerals (lazurite, calcite, pyrite, and sodalite); (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2
Septarian Nodule
Septarian Concretion (CaCO3 + CaMg(CO3)2)
Lapis Lazuli
Na8[Al6Si6O24]n(S,Cl,SO4,OH)2 (Lazurite component)
Chert
Microcrystalline Quartz (SiO2)
Banded Chert (Agate/Jasper blend)
Microcrystalline Quartz (SiO2)
Chert (and/or Flint)
Chert (Cryptocrystalline variety of Quartz, SiO2)
Banded Chert
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Iron-stained)
Chert (Cryptocrystalline Silica, SiO2)
Chert / Jasper / Agate (Chalcedony Group)
Microcrystalline Quartz (SiO2)
Epidote with Quartz and Feldspar
Ca2(Al2,Fe3+)(SiO4)3(OH) (Epidote complex)
Chert (Red/Brown Variety)
Microcrystalline quartz (SiO2)
Lapis Lazuli
Lapis Lazuli (Rock composed primarily of Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Calcite, and Pyrite)
Nephrite Jade
Ca2(Mg,Fe)5Si8O22(OH)2
Yellow Jade (Nephrite or Quartzite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jade-colored Quartzite (SiO2)
Turquoise in Matrix
Hydrous phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Nephrite Jade
Tremolite-Actinolite solid solution, Ca2(Mg,Fe)5Si8O22(OH)2
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
Yellow Jade (Nephrite or Jadeite)
Nephrite: Ca2(Mg,Fe)5Si8O22(OH)2 or Jadeite: NaAlSi2O6