Amethyst, Aquamarine, and Pearl Ring
SiO2 (Amethyst), Be3Al2Si6O18 (Aquamarine), CaCO3 (Pearl)
gemstone
Category
Organic (Biological Organism)
Browse organic (biological organism) specimens identified by the Rock Identifier community.
Learn about Organic (Biological Organism) in the encyclopedia
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Natural Freshwater Pearl
Calcium Carbonate (Aragonite and Calcite), CaCO3
gemstone
Oak-grain Laminate (Industrial/Decorative Furniture Finish)
Melamine Resin-impregnated Decorative Paper on Particleboard (Cellulose/Thermosetting Plastic)
not a rock (synthetic material)
Coquina / Limonite-stained Limestone
Sedimentary Limestone with Iron Oxyhydroxide (FeO(OH)·nH2O)
sedimentary
Ironstone concretion / Limonitic Sandstone
Goethite/Hematite Cemented Sandstone (Hydrated Iron Oxide)
sedimentary
Shale
Shale (Fine-grained clastic sedimentary rock)
sedimentary
Glauconite
Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
mineral
Amber
Succinite (Fossilized Tree Resin)
gemstone
Amber
Succinite
mineral
Lignite (Brown Coal)
Humic Lignite (Carbonaceous sedimentary rock)
sedimentary
Glauconite (Green Sandstone)
Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
sedimentary
Plume Agate
Silicon Dioxide (SiO2) - Chalcedony Variety
mineral
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Petrified wood
Silicified fossil wood, primarily quartz (SiO₂) replacing cellulose
fossil
Fossil gastropod shell
Fossilized marine gastropod; exact genus/species cannot be determined from the image
fossil
Mocha Stone (Dendritic Agate)
Silicon Dioxide (SiO2) with Manganese/Iron inclusions
sedimentary
Amber
Fossilized Tree Resin (Organic Polymer)
gemstone
Mother of Pearl (Nacre)
Calcium Carbonate (Aragonite) with organic conchiolin
gemstone
Coal (Bituminous / Anthracite)
Organic Sedimentary Rock (Carbonaceous Rock)
sedimentary
Coal
Coal (Sedimentary Rock / Organic Rock)
sedimentary
Ambergris
Ambergris (Coprolite-adjacent/Organic secretion)
mineraloid
Quartz River Pebble with Algae
Silicon Dioxide (SiO2) with organic biofilm
metamorphic or igneous
Amber in Matrix
Succinite (Carbon-based organic polymer)
Organic (Sedimentary context)
Pearl
Aragonite and Conchiolin (CaCO3 + organic protein)
mineraloid
Bituminous Coal
Organic sedimentary rock (humic coal)
sedimentary
Fossil Shark Tooth
Carcharodon sp. (likely Otodus or similar Lamniformes order)
sedimentary
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
mineral
Dendritic Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
mineral
Fossiliferous Shale
Carbonaceous Shale (with potential plant/aquatic fossils)
sedimentary
Amber (Copal)
Succinate (Fossilized Tree Resin)
mineraloid
Quartz pebble or seed/crumb
SiO2 (if quartz)
mineral
Amber
Amber (C10H16O)
mineral
Amber
Succinite (Fossilized Tree Resin)
mineraloid
Petrified wood (polished/cut slab)
Silicified fossil wood, commonly quartz/chalcedony (SiO₂) replacing wood tissue
fossil
Raw amber
Fossilized tree resin; primarily polymerized terpenoid resin (succinite when Baltic-type)
gemstone
Petrified Wood
Silicified Wood (SiO2)
fossil
Fossiliferous Shale
Laminated Mudrock with plant fossils
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Amber
Succinite (fossilized tree resin, C10H16O)
fossil
Weathered gray-green rock fragment
Likely shale or mudstone; exact identification requires testing
sedimentary
Glauconitic Sandstone
Glauconitic Quartz-Wacke / Sandstone (Fe(II),Fe(III),Al,Mg)2-3(Si,Al)4O10(OH)2
sedimentary
Garden Quartz
Included Quartz (SiO2 with accessory minerals such as Chlorite, Hematite, or Feldspar)
mineral