Rock Identifier

Category

Synthetic Polymer (Polylactic Acid)

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

Learn about Synthetic Polymer (Polylactic Acid) in the encyclopedia

Yttrium Aluminum Garnet

Yttrium Aluminum Garnet

Zincite

Opalite

Lead Feldspar

Dolomite

Zircon

Orange Calcite

Calcite (Calcium Carbonate (CaCO3)) — mineral

Calcite

Calcium Carbonate (CaCO3)

Green calcite (likely) (Calcite, calcium carbonate (CaCO₃)) — mineral

Green calcite (likely)

Calcite, calcium carbonate (CaCO₃)

Calcite-rich limestone fragment (Limestone, predominantly calcite (CaCO₃), possibly micritic or fossiliferous) — sedimentary

Calcite-rich limestone fragment

Limestone, predominantly calcite (CaCO₃), possibly micritic or fossiliferous

Likely quartz-rich mineral fragment (Quartz (SiO₂), possibly a small piece of milky quartz or calcite) — mineral

Likely quartz-rich mineral fragment

Quartz (SiO₂), possibly a small piece of milky quartz or calcite

Tumbled quartz-rich carbonate rock (Likely massive quartz (SiO₂), possibly calcite-bearing marble or limestone) — mineral

Tumbled quartz-rich carbonate rock

Likely massive quartz (SiO₂), possibly calcite-bearing marble or limestone

Pink calcite (likely iron-stained calcite) (Calcite, CaCO₃; commonly rhombohedral or massive crystalline aggregate) — mineral

Pink calcite (likely iron-stained calcite)

Calcite, CaCO₃; commonly rhombohedral or massive crystalline aggregate

Bornite (Peacock Ore) / Acid-treated Chalcopyrite (Bornite (Cu5FeS4) or Chalcopyrite (CuFeS2)) — mineral

Bornite (Peacock Ore) / Acid-treated Chalcopyrite

Bornite (Cu5FeS4) or Chalcopyrite (CuFeS2)

Quartzite (Metamorphic Quartzite (SiO2)) — metamorphic

Quartzite

Metamorphic Quartzite (SiO2)

White Calcite (Calcium Carbonate (CaCO3)) — mineral

White Calcite

Calcium Carbonate (CaCO3)

Chalcopyrite (Peacock Ore) (Copper Iron Sulfide (CuFeS2)) — mineral

Chalcopyrite (Peacock Ore)

Copper Iron Sulfide (CuFeS2)

Chalcopyrite (Peacock Ore) (Chalcopyrite (CuFeS2)) — mineral

Chalcopyrite (Peacock Ore)

Chalcopyrite (CuFeS2)

Limestone (Calcium carbonate (CaCO3)) — sedimentary

Limestone

Calcium carbonate (CaCO3)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Tumbled yellow chalcedony (likely citrine or yellow jasper) (Microcrystalline quartz, SiO₂; exact identification is uncertain from the photograph) — mineral

Tumbled yellow chalcedony (likely citrine or yellow jasper)

Microcrystalline quartz, SiO₂; exact identification is uncertain from the photograph

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

Limestone (specifically Fossiliferous Limestone)

Calcium Carbonate (CaCO3)

Diamond (appearing as a jewelry centerpiece) (Diamond (Formula: C)) — mineral

Diamond (appearing as a jewelry centerpiece)

Diamond (Formula: C)

Calcite crystal cluster (Calcite (calcium carbonate, CaCO₃), likely honey or pale-orange calcite) — mineral

Calcite crystal cluster

Calcite (calcium carbonate, CaCO₃), likely honey or pale-orange calcite

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Calcite (Calcium Carbonate (CaCO3)) — mineral

Calcite

Calcium Carbonate (CaCO3)

Carrara Marble (Recrystallized Calcite (CaCO3)) — metamorphic

Carrara Marble

Recrystallized Calcite (CaCO3)

Gray Limestone Fragment (Limestone (CaCO3)) — sedimentary

Gray Limestone Fragment

Limestone (CaCO3)

Probable amber fragment (Amber (fossilized plant resin; chiefly amorphous organic resin, commonly dominated by succinite)) — gemstone

Probable amber fragment

Amber (fossilized plant resin; chiefly amorphous organic resin, commonly dominated by succinite)

Chalky limestone (Calcite-rich limestone; chiefly calcium carbonate (CaCO₃)) — sedimentary

Chalky limestone

Calcite-rich limestone; chiefly calcium carbonate (CaCO₃)

Honey calcite crystal cluster (Calcite (calcium carbonate, CaCO₃)) — mineral

Honey calcite crystal cluster

Calcite (calcium carbonate, CaCO₃)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Limestone (Sedimentary rock composed primarily of Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Sedimentary rock composed primarily of Calcium Carbonate (CaCO3)

Limestone (Sedimentary rock composed primarily of Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Sedimentary rock composed primarily of Calcium Carbonate (CaCO3)

Tumbled light-colored stone, possibly quartzite or limestone (Indeterminate; likely quartzite (mostly SiO₂) or calcitic limestone (CaCO₃)) — metamorphic

Tumbled light-colored stone, possibly quartzite or limestone

Indeterminate; likely quartzite (mostly SiO₂) or calcitic limestone (CaCO₃)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Fossiliferous limestone (Bioclastic limestone, primarily calcite (CaCO₃), with possible shell or coral fossil molds) — fossil

Fossiliferous limestone

Bioclastic limestone, primarily calcite (CaCO₃), with possible shell or coral fossil molds

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Limestone with Lichen/Moss (Calcium Carbonate (CaCO3)) — sedimentary

Limestone with Lichen/Moss

Calcium Carbonate (CaCO3)

Jewelry Chain with Blue and Clear Gemstones (Likely Cubic Zirconia) (Cubic Zirconia (ZrO₂), Silver or White Gold/Platinum Alloy) — Mineral (synthetic) and Metal (precious/base)

Jewelry Chain with Blue and Clear Gemstones (Likely Cubic Zirconia)

Cubic Zirconia (ZrO₂), Silver or White Gold/Platinum Alloy

Mineral (synthetic) and Metal (precious/base)

Weathered fossiliferous limestone, possibly coral or stromatoporoid (Calcitic limestone, predominantly CaCO₃; fossil identity cannot be confirmed from one photograph) — sedimentary

Weathered fossiliferous limestone, possibly coral or stromatoporoid

Calcitic limestone, predominantly CaCO₃; fossil identity cannot be confirmed from one photograph

Flagstone paving (likely sandstone or limestone) (Clastic sandstone or carbonate limestone; exact identification requires testing) — sedimentary

Flagstone paving (likely sandstone or limestone)

Clastic sandstone or carbonate limestone; exact identification requires testing

Tumbled banded calcite (often sold as “onyx” or green onyx) (Calcite, CaCO₃; commonly banded cave/travertine calcite) — mineral

Tumbled banded calcite (often sold as “onyx” or green onyx)

Calcite, CaCO₃; commonly banded cave/travertine calcite

Marble (Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)) — metamorphic

Marble

Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)

Fossiliferous Limestone (Crinoidal) (Calcite-bearing bioclastic packstone (CaCO3)) — sedimentary

Fossiliferous Limestone (Crinoidal)

Calcite-bearing bioclastic packstone (CaCO3)

Fossiliferous limestone with possible ammonite or shell impressions (Calcitic limestone, chiefly CaCO₃; fossils may include ammonoids or bivalves) — fossil

Fossiliferous limestone with possible ammonite or shell impressions

Calcitic limestone, chiefly CaCO₃; fossils may include ammonoids or bivalves

Calcite (with iron oxide staining) (Calcium Carbonate (CaCO3)) — mineral

Calcite (with iron oxide staining)

Calcium Carbonate (CaCO3)