Clear Quartz Crystal
Quartz (Silicon Dioxide, SiO2)
mineral
Category
Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material)
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Learn about Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material) in the encyclopedia
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White seed-bead gemstone strand, likely freshwater pearl or shell pearl
Pearl: nacreous calcium carbonate, chiefly aragonite (CaCO₃) in conchiolin; identification uncertain from image
gemstone
Chert (Basanite / Jasperoid)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Amber
Succinite (specifically Baltic Amber) - Formula: C10H16O (approximate)
Organic Mineraloid
Petrified Wood
Silicified wood (Quartz replacement, SiO2)
fossil
Amazonite
Microcline (Potassium Feldspar), KAlSi3O8
mineral
Bloodstone (Heliotrope)
Silicon Dioxide (SiO2) with inclusions of Hematite or Iron oxide
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Flower Agate (Plume Agate)
Chalcedony (Silicon Dioxide) with Spherulitic Inclusions - SiO2
mineral
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
sedimentary
Moonstone
Orthoclase Feldspar ((K,Na)AlSi3O8)
mineral
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Travertine (Tufa)
Chemical Sedimentary Rock (CaCO3)
sedimentary
Pearl
Calcium Carbonate (Aragonite) - CaCO3
mineral
Banded Jasper
Silicate Mineral (Microcrystalline Quartz / SiO2)
sedimentary
Quartz Druzy on Matrix (likely Agate or Jasper)
Silicon Dioxide (SiO2) with various mineral inclusions
mineral
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
gemstone
Rough Ruby
Corundum (Al2O3 with Chromium impurities)
mineral
Amazonite
Microcline feldspar (KAlSi3O8)
mineral
Amber
Succinite (fossilized resin, C10H16O)
mineral
Petrified Wood
Silicified wood (primarily Quartz, SiO2)
fossil
Jasper
Silicon Dioxide (Microcrystalline Quartz, SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Dalmatian Stone
Dalmatian Jasper / Aplite
igneous
Pearl (Biogenic Mineraloid)
Calcium carbonate (CaCO3) primarily as Aragonite
mineral
Petrified Wood
Silicified Wood (SiO2)
fossil
Hag Stone (Adder Stone / Geode-bearing Pebble)
Sedimentary Rock with Cavity (often Quartzite, Limestone, or Sandstone)
sedimentary
Jasper
Silicon dioxide (Microcrystalline quartz, SiO2)
mineral
Coprolite
Fossilized Feces
fossil
Green glass-like cabochon, likely synthetic glass or resin
Unidentified green transparent material; possibly molded glass, synthetic spinel, or resin
gemstone
Sandstone (likely Fossiliferous Sandstone)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
mineral
Fossilized Shark Tooth
Chondrichthyes (class) fossilized tooth
fossil
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 principal component)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil
Pearl (as a Biogenic Mineral)
Calcium Carbonate (mostly Aragonite) with Conchiolin; CaCO3
mineral
Jasper
Microcrystalline Quartz (SiO2)
gemstone
Amber
Succinite (fossilized resin)
mineraloid
Blue-green copper mineral specimen, likely chrysocolla-bearing rock
Chrysocolla, hydrated copper phyllosilicate: approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O; possibly mixed with malachite or chrysocolla matrix
mineral
Fossilized Bivalve Shell
Bivalvia (Phylum Mollusca)
fossil
Ironstone Concretion (Boxwork)
Siderite-Limonite Concretion (FeO(OH)·nH2O)
sedimentary