Limestone (River Pebble)
Calcium Carbonate (CaCO3)
Category
Browse synthetic polymer (polylactic acid) specimens identified by the Rock Identifier community.
Limestone (River Pebble)
Calcium Carbonate (CaCO3)
Calcite
Calcite (Calcium Carbonate, CaCO3)
Marble
Metamorphosed Limestone (principally CaCO3)
Amber
Succinite (specifically for Baltic amber); approximate formula C10H16O
Pyrite in Quartzite/Graphite Matrix
Iron Sulfide (FeS2)
Fluorite Tower
Calcium Fluoride (CaF2)
Iron-stained Quartz (with Limonite/Hematite)
Silicon Dioxide (SiO2) with Iron Oxide inclusions (FeO(OH) or Fe2O3)
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
Brimstone (Native Sulfur)
Native Sulfur (S)
Green Fluorite
Calcium Fluoride (CaF2)
Fluorite
Calcium Fluoride (CaF2)
Sulfur on Quartz
Native Sulfur (S8) with Quartz (SiO2)
Fluorite
Calcium fluoride (CaF2)
Pyrite
Iron Sulfide (FeS2)
Pyrite
Iron Disulfide (FeS2)
Pyrite
Iron Sulfide (FeS2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Lapis Lazuli
A metamorphic rock primarily composed of lazurite (Na,Ca)8[(S,SO4,Cl)2|(Al6Si6O24)], calcite (CaCO3), and pyrite (FeS2).
Black Tourmaline (Schorl)
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Sapphire
Corundum (Al₂O₃) with trace elements causing color variations.
Orange Calcite
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Limestone
Limestone (Calcium Carbonate - CaCO3)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Chalk
Calcium Carbonate (CaCO3)
Siltstone
Siltstone (composed of clastic quartz and feldspar)
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock
Quartzite Pebble
Quartzite (composed primarily of Silica, SiO2)
Quartzite
Quartzite (primarily SiO2)
Banded Calcite (often sold as Mexican Onyx or Aragonite)
Calcite/Aragonite (Calcium Carbonate, CaCO3)
Orange Calcite
Calcite (Calcium Carbonate, CaCO3)
Basalt (River Stone/Pebble)
Basalt (Extrusive Igneous Rock)
Quartzite with Feldspar
Quartzite (mainly SiO2) with inclusions of Potassium Feldspar (KAlSi3O8)
Chert (Field-collected specimen)
Chert (Crystalline Silica, SiO2)
Chert (and Chert-Jasper mix)
Microcrystalline Quartz (SiO2)
Gray Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Quartzite
Quartzite (SiO2)
Wonderstone
Banded Rhyolite (SiO2 with impurities)
Quartzite
Quartzite (primarily SiO2)
Sandstone (Quartz-rich)
Arenite (SiO2 based)
Honey Calcite
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)