Rock Identifier

Category

Synthetic Polymer (Polylactic Acid)

Browse synthetic polymer (polylactic acid) specimens identified by the Rock Identifier community.

Chert (Iron-stained) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

sedimentary
Limonite-stained Quartz / Quartzite (Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)) — sedimentary or metamorphic

Limonite-stained Quartz / Quartzite

Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)

sedimentary or metamorphic
Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

metamorphic
Aragonite / Calcite Geode (Calcium Carbonate (CaCO3)) — mineral

Aragonite / Calcite Geode

Calcium Carbonate (CaCO3)

mineral
Pink Quartzite (Quartzite (primarily SiO2)) — metamorphic

Pink Quartzite

Quartzite (primarily SiO2)

metamorphic
Limestone with Quartz or Calcite Veining (Calcium Carbonate (CaCO3) matrix with SiO2 or CaCO3 inclusions) — sedimentary

Limestone with Quartz or Calcite Veining

Calcium Carbonate (CaCO3) matrix with SiO2 or CaCO3 inclusions

sedimentary
Yellow Calcite (Banded Calcite) (Calcium Carbonate (CaCO3)) — mineral

Yellow Calcite (Banded Calcite)

Calcium Carbonate (CaCO3)

mineral
Fossiliferous Limestone with Brachiopod shell (Calcium carbonate (CaCO3)) — sedimentary

Fossiliferous Limestone with Brachiopod shell

Calcium carbonate (CaCO3)

sedimentary
Sand Grain (Silica/Quartz Grain) (Silicon Dioxide (SiO2)) — sedimentary

Sand Grain (Silica/Quartz Grain)

Silicon Dioxide (SiO2)

sedimentary
Peridot (Gem-quality Olivine) (Magnesium Iron Silicate ((Mg, Fe)2SiO4)) — mineral

Peridot (Gem-quality Olivine)

Magnesium Iron Silicate ((Mg, Fe)2SiO4)

mineral
Marble (Recrystallized Calcite (CaCO3) Rock) — metamorphic

Marble

Recrystallized Calcite (CaCO3) Rock

metamorphic
Marble (Recrystallized Calcite (CaCO3)) — metamorphic

Marble

Recrystallized Calcite (CaCO3)

metamorphic
Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

mineral
Red Sandstone (Arenite (primarily Quartz with Iron Oxide coating)) — sedimentary

Red Sandstone

Arenite (primarily Quartz with Iron Oxide coating)

sedimentary
Banded Calcite (Mexican Onyx) (Calcite (CaCO3)) — mineral

Banded Calcite (Mexican Onyx)

Calcite (CaCO3)

mineral
Coquina / Fossiliferous Limestone (Calcareous bioclastic sedimentary rock (CaCO3)) — sedimentary

Coquina / Fossiliferous Limestone

Calcareous bioclastic sedimentary rock (CaCO3)

sedimentary
Marble (Recrystallized Carbonate Rock (CaCO3)) — metamorphic

Marble

Recrystallized Carbonate Rock (CaCO3)

metamorphic
Chert (Iron-stained) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

sedimentary
White Marble (Recrystallized Calcite (CaCO3)) — metamorphic

White Marble

Recrystallized Calcite (CaCO3)

metamorphic
Quartzite (Quartzite (composed primarily of SiO2)) — metamorphic

Quartzite

Quartzite (composed primarily of SiO2)

metamorphic
Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

mineral
Cobaltian Calcite (Cobaltoan Calcite) (Cobalt-bearing Calcite (Ca,Co)CO3) — mineral

Cobaltian Calcite (Cobaltoan Calcite)

Cobalt-bearing Calcite (Ca,Co)CO3

mineral
Shale (Shale (composition varies: primarily clay minerals and quartz)) — sedimentary

Shale

Shale (composition varies: primarily clay minerals and quartz)

sedimentary
Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

metamorphic
Unakite (Epidotized Granite) — metamorphic

Unakite

Epidotized Granite

metamorphic
Aragonite Star Cluster (Aragonite (Calcium Carbonate, CaCO3)) — mineral

Aragonite Star Cluster

Aragonite (Calcium Carbonate, CaCO3)

mineral
Rhodochrosite (Manganese Carbonate (MnCO3)) — mineral

Rhodochrosite

Manganese Carbonate (MnCO3)

mineral
Limestone (specifically Fossiliferous Limestone) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (specifically Fossiliferous Limestone)

Calcium Carbonate (CaCO3)

sedimentary
Quartzite River Rock (Quartzite (primarily SiO2)) — metamorphic

Quartzite River Rock

Quartzite (primarily SiO2)

metamorphic
Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

sedimentary
Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

metamorphic
Scoria with Calcite Infills (Vesicular Basalt with secondary Calcification (CaCO3)) — igneous

Scoria with Calcite Infills

Vesicular Basalt with secondary Calcification (CaCO3)

igneous
Azurite Geode (Azurite (Cu3(CO3)2(OH)2)) — mineral

Azurite Geode

Azurite (Cu3(CO3)2(OH)2)

mineral
Oolitic Ironstone (Sedimentary Ooidal Ironstone (Limonite/Hematite mixture)) — sedimentary

Oolitic Ironstone

Sedimentary Ooidal Ironstone (Limonite/Hematite mixture)

sedimentary
Fossiliferous Limestone (Calcareous biomicrite / Bioclastic limestone) — sedimentary

Fossiliferous Limestone

Calcareous biomicrite / Bioclastic limestone

sedimentary
Aragonite Star Cluster (Aragonite (Sputnik habit) - CaesarCO3) — mineral

Aragonite Star Cluster

Aragonite (Sputnik habit) - CaesarCO3

mineral
Red Sandstone (Arenite (with Iron Oxide / Hematite), Formula: SiO2 (Quartz) + Fe2O3 (Hematite coating)) — sedimentary

Red Sandstone

Arenite (with Iron Oxide / Hematite), Formula: SiO2 (Quartz) + Fe2O3 (Hematite coating)

sedimentary
Orange Quartzite (River Pebble) (Quartzite (primarily SiO2)) — metamorphic

Orange Quartzite (River Pebble)

Quartzite (primarily SiO2)

metamorphic
Yellow Calcite (Calcium Carbonate (CaCO3)) — mineral

Yellow Calcite

Calcium Carbonate (CaCO3)

mineral
Coquina (Biogenic Limestone (Calcitic shells)) — sedimentary

Coquina

Biogenic Limestone (Calcitic shells)

sedimentary
Granite (Granite (Phaneritic Igneous Rock / Quartz, Feldspar, Mica)) — igneous

Granite

Granite (Phaneritic Igneous Rock / Quartz, Feldspar, Mica)

igneous
Quartzite (River Cobble) (Metamorphic Quartz-rich Rock) — metamorphic

Quartzite (River Cobble)

Metamorphic Quartz-rich Rock

metamorphic