Travertine
Calcareous Tufa (CaCO3)
sedimentary
Category
Synthetic Polymer (Polylactic Acid)
Browse synthetic polymer (polylactic acid) specimens identified by the Rock Identifier community.
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Agate
Silicon Dioxide (SiO2) - Banded Chalcedony
mineral
Fossiliferous Limestone with Rugose Coral
Calcite (CaCO3) matrix containing Rugosa (order of extinct solitary and colonial corals)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Banded Iron Formation (Red Jasper and Hematite Chert)
Banded Iron Formation (BIF); Fe2O3 (Hematite) + SiO2 (Quartz/Jasper)
sedimentary
Malachite
Malachite (Copper Carbonate Hydroxide, Cu2CO3(OH)2)
mineral
Chert (specifically Tan/Yellow Chert)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
sedimentary
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Pyrite
Pyrite (FeS₂)
Mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Quartzite
Quartzite (primarily SiO2)
Metamorphic
Malachite
Malachite, Cu2(CO3)(OH)2
Mineral
Galena
Lead(II) sulfide (PbS)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Pyrite in Matrix (likely Quartz or Schist matrix)
Iron Sulfide (FeS2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Rough Green Fluorite
Fluorite (Calcium Fluoride - CaF2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Gold Ore / Native Gold
Native Gold (Au)
mineral
Black Onyx
Silicon Dioxide (SiO2) - Chalcedony variant
mineral
White Agate (Chalcedony)
Silicon Dioxide (SiO2)
mineral
Rhodochrosite
Manganese Carbonate (MnCO3)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Oolitic Limestone
Oolitic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Amygdaloidal Basalt
Amygdaloidal Basalt (extrusive volcanic rock with mineral inclusions)
igneous
Pink Granite
Phaneritic Acidic Igneous Rock (primarily SiO2, Al2O3, K2O)
igneous
Cobaltian Calcite (Cobaltoan Calcite)
Cobaltian Calcite (CaCO3 with Co2+ substitution)
Mineral
Blue Banded Agate (Dyed)
Silicon Dioxide (SiO2) - Variety of Chalcedony
mineral
Aragonite Star Cluster (or Aragonite Sputnik)
Aragonite (Orthorhombic Calcium Carbonate, CaCO3)
mineral
Picasso Stone
Metamorphic Limestone (Marble)
metamorphic
Fluorite (Polished Point/Tower)
Calcium Fluoride (CaF2)
mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Sulfur
Native Sulfur (S8)
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Blue Apatite
Apatite - Ca5(PO4)3(F,Cl,OH) (Calcium phosphate with Fluorine, Chlorine, or Hydroxyl)
mineral
Honeycomb Calcite
Calcite (Calcium Carbonate, CaCO3)
sedimentary
Fluorite
Calcium Fluoride (CaF2)
Mineral