Marble
Recrystallized Limestone (CaCO3)
Category
Browse organic (paper and cellulose) specimens identified by the Rock Identifier community.
Marble
Recrystallized Limestone (CaCO3)
Wallboard/Drywall (Gypsum-based)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Limestone
Calcium carbonate (CaCO3)
Shungite
Carbonaceous rock (primarily amorphous carbon)
Chalk
Calcium Carbonate (CaCO3)
Graphite
Graphite (Native Carbon, C)
Selenite (Gypsum)
Hydrous calcium sulfate (CaSO4·2H2O)
Marble (White)
Metamorphosed Limestone (mainly CaCO3)
White Marble
Recrystallized Calcite (CaCO3)
Marble
Recrystallized Calcite Rock (CaCO3)
Marble
Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)
Chalk (Limestone variant)
Calcium Carbonate (CaCO3)
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
White Marble (Industrial/Architectural)
Recrystallized Calcite (CaCO3)
Selenite
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Chalk (Sedimentary Limestone)
Calcium Carbonate (CaCO3) - Bioclastic Limestone
Barite
Barium Sulfate (BaSO4)
White Marble
Calcite-rich Metasomatized Carbonate (CaCO3)
Chalk / Sedimentary Limestone
Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock
Calcite
Calcite (CaCO₃)
Calcite
Calcite (CaCO 3)
Calcite
Calcite (Mineral; CaCO₃)
Fossilized Coral (Petoskey Stone or Rugose Coral)
Antophyllum (Hexagonaria) or Scleractinia (CaCO3)
Fossil Coral
Cnidaria Anthozoa (Fossilized)
Purple Agate (Dyed Chalcedony)
SiO2 (Silicon Dioxide) with organic dyes
Dendritic Limestone
Calcite with Manganese Oxide (Manganese Dendrites)
Zebra Rock / Zebra Marble
Banded Limestone-Marble Transition
Fossil Coral (Rugosa or Solitary Coral)
Rugosa (Order), often referred to as 'Horn Coral' (Lithostrotionella or Grewingkia)
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2 - Silicon Dioxide)
Inspirational River Stone (Quartzite)
Metamorphosed Quartz-rich Rock (Quartzite) with SiO2 composition
Ceramic or Polished Stone Heart (Anthropogenic Material)
Glazed Ceramic (Silicon Dioxide based coating on Alumina Silicate body) or Polished Limestone/Marble (Calcium Carbonate, CaCO3)
Painted Pet Rock (Quartzite/Sandstone base)
Silicon Dioxide (SiO2) with anthropomorphic acrylic embellishments
Painted Garden Rock (likely Granite or Limestone base)
Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3) based substrate with Acrylic/Enamel pigments
Biotite (Black Mica)
Biotite (K(Mg,Fe++)3AlSi3O10(OH,F)2)
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Cream Marble (Speckled)
Metamorphosed Limestone (mainly CaCO3)
White Marble
Recrystallized Calcite (CaCO3)
Banded Iron Formation
Banded Iron Formation (BIF)
Pet Rock (Man-made Quartzite or Granite Cobble)
Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
Sandstone
Arenite (primarily SiO2)