Ambergris (Geological/Organic Specimen)
Ambra grisea (Produced by Physeter macrocephalus)
organic material
Category
Man Made Object (Metalwork)
Browse man made object (metalwork) specimens identified by the Rock Identifier community.
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Polished fossilized ammonite or nautiloid shell
Ammonoidea or Nautiloidea; originally aragonitic shell, commonly replaced by calcite or chalcedony
fossil
Chalcedony Pebble (Carnelian / Quartz Pebble)
Silicon Dioxide (SiO2)
mineral
Flint / Chert
Microcrystalline quartz (SiO2)
sedimentary
Diorite
Diorite (Plagioclase feldspar and amphibole/biotite)
igneous
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Greenstone
Metamorphic mafic rock (chlorite-actinolite-epidote schist)
metamorphic
Sandstone
Sandstone (composed predominantly of Quartz, SiO2, with Feldspar and Clay minerals)
sedimentary
Chert (Flint / Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint Arrowhead)
Silicon Dioxide (SiO2)
sedimentary
Black Chert River Stone
Cryptocrystalline Quartz (SiO2)
sedimentary
Malachite
Malachite (Cu2CO3(OH)2)
mineral
Swirled Agate Bead
Silicon Dioxide (SiO2)
mineral
Chert (Black Chert or Flint)
Silicon Dioxide (SiO2)
sedimentary
Marble
Metamorphic Limestone (CaCO3)
metamorphic
Chert (Flint Nodules)
Cryptocrystalline Quartz (SiO2)
sedimentary
Tektite (Indochinite)
Tektite (Amorphous Silica Glass)
igneous
Natural Pearl (appearing in a jewelry setting)
Calcium Carbonate (mostly Aragonite), CaCO3 with Conchiolin
mineral
Rough Diamond
Diamond (pure Carbon, C)
mineral
Amethyst (Tumbled Cabinet Stone)
Silicon Dioxide (SiO2) with iron impurities
mineral
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Pink Granite
Intrusive Igneous Rock (high K-feldspar content)
igneous
Chert
Cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone (likely Quartzose Sandstone)
Arenite
sedimentary
Granite
Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)
igneous
Diamond
Native Carbon (C)
mineral
Sandstone (Quartz Arenite)
Sandstone (dominated by SiO2 quartz grains)
sedimentary
Chert (Nodule)
Chert (Silicon Dioxide, SiO2)
sedimentary
White calcite (likely tumbled calcite or marble fragment)
Calcite, calcium carbonate (CaCO₃); if the specimen is granular and rock-like, it may be marble, a calcite-rich metamorphic rock
mineral
Sandstone (specifically Arkose or Quartz Arenite)
Arenite (primarily SiO2 with possible Feldspar)
sedimentary
Coquina (Fossiliferous Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Nephrite Jade
Ca2(Mg,Fe)5Si8O22(OH)2 (Tremolite-Actinolite series)
metamorphic
Ferruginous Sandstone (Ironstone)
Clastic Sedimentary Rock (composed of SiO2 with Fe2O3/FeO(OH) cement)
sedimentary
Gold
Gold (Au)
mineral
Banded Calcite (often sold as 'Mexican Onyx')
Calcite (Calcium Carbonate - CaCO3)
sedimentary
Tumbled pink chalcedony (likely pink agate/jasper)
Microcrystalline quartz, SiO₂, with iron-oxide coloring
mineral
Polished orange agate or chalcedony
Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/agate
mineral
Tumbled reddish-brown stone, likely jasper
Jasper (microcrystalline quartz, SiO₂), possibly red jasper or jasper-rich chert
mineral
Tumbled carnelian (red-orange chalcedony)
Carnelian, a cryptocrystalline variety of quartz: SiO₂
gemstone
Polished carnelian
Carnelian, a red-orange variety of chalcedony (microcrystalline quartz, SiO₂)
gemstone
Polished tiger’s-eye
Chatoyant quartz, mainly fibrous crocidolite pseudomorphed by quartz (SiO₂)
mineral