Rock Identifier

Category

Synthetic Polymer (Polylactic Acid)

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

Metal Alloy (Jewelry) (Not a naturally occurring rock or mineral; likely a metal alloy for jewelry. Possible compositions include sterling silver (92.5% silver, 7.5% copper), or other silver/gold alloys.) — Man-made Material (jewelry, metal alloy)

Metal Alloy (Jewelry)

Not a naturally occurring rock or mineral; likely a metal alloy for jewelry. Possible compositions include sterling silver (92.5% silver, 7.5% copper), or other silver/gold alloys.

Man-made Material (jewelry, metal alloy)

Agate (Agate (a cryptocrystalline variety of Quartz, SiO₂)) — Mineral

Agate

Agate (a cryptocrystalline variety of Quartz, SiO₂)

Quartzite (Quartzite) — Metamorphic rock

Quartzite

Quartzite

Metamorphic rock

Goldstone (Red) (Aventurine Glass (SiO2 + Cu)) — Synthetic Glass (Often categorized as a simulated mineral)

Goldstone (Red)

Aventurine Glass (SiO2 + Cu)

Synthetic Glass (Often categorized as a simulated mineral)

Chert (Chert (microcrystalline quartz)) — sedimentary

Chert

Chert (microcrystalline quartz)

Hematite (beads) (Hematite (Fe₂O₃)) — Mineral

Hematite (beads)

Hematite (Fe₂O₃)

Orange Calcite (Calcite (CaCO3)) — Mineral

Orange Calcite

Calcite (CaCO3)

Amazonite (Amazonite (KAlSi3O8, a variety of Microcline)) — Mineral

Amazonite

Amazonite (KAlSi3O8, a variety of Microcline)

Mother of Pearl (Nacre) (Calcium Carbonate (primarily aragonite, with conchiolin)) — Organic Gemstone/Biomineral

Mother of Pearl (Nacre)

Calcium Carbonate (primarily aragonite, with conchiolin)

Organic Gemstone/Biomineral

Calcite (commonly referred to as Orange Calcite or Honey Calcite given its color) (Calcite) — Mineral

Calcite (commonly referred to as Orange Calcite or Honey Calcite given its color)

Calcite

Banded Agate (likely Carnelian Agate or Sardonyx) (Agate is a common name for a microcrystalline variety of Quartz (SiO₂), specifically a form of Chalcedony.) — Sedimentary Rock (technically a variety of Chalcedony)

Banded Agate (likely Carnelian Agate or Sardonyx)

Agate is a common name for a microcrystalline variety of Quartz (SiO₂), specifically a form of Chalcedony.

Sedimentary Rock (technically a variety of Chalcedony)

Pyrite (Pyrite (Iron Disulfide), FeS2) — Mineral

Pyrite

Pyrite (Iron Disulfide), FeS2

Sulfur on Aragonite (Sulfur (S) and Aragonite (CaCO3)) — Mineral

Sulfur on Aragonite

Sulfur (S) and Aragonite (CaCO3)

Fluorite (often referred to casually as 'Fluorspar' in industrial contexts) (Fluorite (CaF2)) — Mineral

Fluorite (often referred to casually as 'Fluorspar' in industrial contexts)

Fluorite (CaF2)

Sodalite (Sodalite (Na4Al3Si3O12Cl)) — Mineral

Sodalite

Sodalite (Na4Al3Si3O12Cl)

Sandstone (Sandstone (various mineral compositions)) — Sedimentary

Sandstone

Sandstone (various mineral compositions)

Pyrite (Iron Pyrite (FeS₂)) — Mineral

Pyrite

Iron Pyrite (FeS₂)

Quartz (Silicon Dioxide (SiO2)) — Mineral

Quartz

Silicon Dioxide (SiO2)

Gneiss (Gneiss (a metamorphic rock)) — Metamorphic

Gneiss

Gneiss (a metamorphic rock)

Fluorite in Matrix (Fluorite (CaF2) within a host rock matrix) — Mineral

Fluorite in Matrix

Fluorite (CaF2) within a host rock matrix

Gold (Aurum (Au)) — Mineral (Metal)

Gold

Aurum (Au)

Mineral (Metal)

Chert / Flint (Chert (varieties include Flint)) — Sedimentary

Chert / Flint

Chert (varieties include Flint)

Sandstone (Arenite (general term for sandstone)) — Sedimentary Rock

Sandstone

Arenite (general term for sandstone)

Sedimentary Rock

Quartz (Quartz (Silicon Dioxide, SiO2)) — Mineral

Quartz

Quartz (Silicon Dioxide, SiO2)

Greisen (Greisen) — Metamorphic

Greisen

Greisen

Chrysocolla (Chrysocolla (Cu,Al)2H2Si2O5(OH)4·nH2O) — Mineral

Chrysocolla

Chrysocolla (Cu,Al)2H2Si2O5(OH)4·nH2O

Granite (Granite (a common rock type, not a single mineral species)) — Igneous

Granite

Granite (a common rock type, not a single mineral species)

Quartz (Quartz (SiO2 - Silicon Dioxide)) — Mineral

Quartz

Quartz (SiO2 - Silicon Dioxide)

Sodalite (Sodalite (Na4Al3Si3O12Cl)) — Mineral

Sodalite

Sodalite (Na4Al3Si3O12Cl)

Tiger's Eye (Silicon dioxide (SiO2) with fibrous inclusions of crocidolite (riebeckite) that have been altered to limonite and then replaced by quartz) — Mineral

Tiger's Eye

Silicon dioxide (SiO2) with fibrous inclusions of crocidolite (riebeckite) that have been altered to limonite and then replaced by quartz

Quartz (Silicon Dioxide (SiO₂)) — Mineral

Quartz

Silicon Dioxide (SiO₂)

Calcite (Calcite (Mineral; CaCO₃)) — Mineral

Calcite

Calcite (Mineral; CaCO₃)

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Goldstone (Brown/Gold variety) (Aventurine Glass (SiO2 with Copper inclusions)) — Synthetic/Man-made glass (often mistaken for a mineral)

Goldstone (Brown/Gold variety)

Aventurine Glass (SiO2 with Copper inclusions)

Synthetic/Man-made glass (often mistaken for a mineral)

Glazed Ceramic Tile (Fused Silicate-Clay composite) — Synthetic (Man-made material mimicking natural stone)

Glazed Ceramic Tile

Fused Silicate-Clay composite

Synthetic (Man-made material mimicking natural stone)

Quartz (Quartz (SiO₂)) — Mineral

Quartz

Quartz (SiO₂)

Quartzite (Quartzite) — Metamorphic rock

Quartzite

Quartzite

Metamorphic rock

Quartz (Silicon Dioxide (SiO₂)) — Mineral

Quartz

Silicon Dioxide (SiO₂)

Blue Quartzite (Quartzite (specifically a variety enriched with blue-coloring minerals)) — Metamorphic Rock

Blue Quartzite

Quartzite (specifically a variety enriched with blue-coloring minerals)

Metamorphic Rock

Fossil Coral (Fossilized Scleractinia or Tabulata (various genera/species)) — Sedimentary

Fossil Coral

Fossilized Scleractinia or Tabulata (various genera/species)

Banded Chert or Chert with Quartz Veins (Chert (SiO2)) — Sedimentary

Banded Chert or Chert with Quartz Veins

Chert (SiO2)

Sandstone (Arenite or Sandstone) — Sedimentary Rock

Sandstone

Arenite or Sandstone

Sedimentary Rock