Malachite and Azurite on Gossan (Ironstone Matrix)
Cu2CO3(OH)2 (Malachite) on FeO(OH)·nH2O (Limonite/Gossan)
Category
Browse synthetic polymer (polylactic acid) specimens identified by the Rock Identifier community.
Malachite and Azurite on Gossan (Ironstone Matrix)
Cu2CO3(OH)2 (Malachite) on FeO(OH)·nH2O (Limonite/Gossan)
Quartzite
Silicon Dioxide (SiO2)
Quartzite
Quartzite (SiO2)
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide - SiO2)
Black Marble
Recrystallized Carbonate Rock (CaCO3)
Lazulite
Magnesium Aluminum Phosphate Hydroxide (MgAl2(PO4)2(OH)2)
Quartzite
Quartzite (primarily SiO2)
Limestone
Calcium Carbonate (CaCO3)
Banded Calcite (often sold as 'Mexican Onyx')
Calcium Carbonate (CaCO3)
Yellow Calcite
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Quartzite Pebble
Recrystallized Quartz (SiO2)
Chalk (Sedimentary Pebble)
Calcium Carbonate (CaCO3) - Biogenic Limestone
Coquina
Biogenic Limestone (Calcite / CaCO3)
Quartzite Pebbles
Quartzite (SiO2)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Quartzite
Quartzite (SiO2)
Quartzite
Quartzite (primarily SiO2)
Gneiss (Metamorphic Cobble)
Gneiss (High-grade Regional Metamorphic Rock)
Milky Quartz with Hematite Staining
Silicon Dioxide (SiO2)
Coquina
Biogenic Limestone (mostly Calcium Carbonate, CaCO3)
White Calcite (Dogtooth Spar or Crystalline Calcite)
Calcite (Calcium Carbonate, CaCO3)
Fossiliferous Sedimentary Rock (Coquina/Limestone)
Fossiliferous Calcarenite / Bioclastic Limestone
Pyrite
Iron Sulfide (FeS2)
Limestone (Travertine/Tufa variant)
Calcium Carbonate (CaCO3)
Quartzite
Quartzite (predominantly SiO2)
Fossiliferous Limestone Pebble
Biogenic Sedimentary Rock (CaCO3)
Yellow Quartzite (Citrine-colored Quartz)
Silicon Dioxide (SiO2)
Fossiliferous Limestone (Coral Fossil)
Calcium Carbonate (CaCO3) with Colonial Coral inclusions
Quartzite
Quartzite (SiO2)
Pink Granite
Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)
Limestone (Beach Pebble)
Sedimentary Calcium Carbonate (CaCO3)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Orange Calcite
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Aragonite (Star Cluster or Twinned variety)
Aragonite (Calcium Carbonate, CaCO3)
Red Quartzite (Stream-rounded Cobble)
Meta-quartzite (SiO2 with Hematite impurities)
Quartzite
Quartzite (composed primarily of Quartz, SiO2)
Coquina
Coquina (Biogenic Limestone / CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Quartzite (Milky)
Metamorphic rock predominantly composed of Quartz (SiO2)
Lapis Lazuli
Lapis lazuli (Mainly Lazurite: Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)