Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)
sedimentary
Category
Organic (Pseudo Geological)
Browse organic (pseudo geological) specimens identified by the Rock Identifier community.
Fossiliferous Limestone
Calcite-rich Sedimentary Rock (CaCO3)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
mineral
Fancy Jasper (Agate/Chert mix)
Silicon Dioxide (SiO2) with impurities
sedimentary
Water and Silt (Sedimentary Environment)
Suspended Sediment / H2O (dihydrogen monoxide)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Ironstone Concretion
Siderite or Hematite Concretion
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Amber
Succinite (specific to Baltic amber), fossilized tree resin
mineraloid
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and organic impurities
sedimentary
Banded Chert
Microcrystalline silicon dioxide (SiO2)
sedimentary
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
Mineral (Variety of Chalcedony)
Travertine (often colloquially called Tufa)
Chemical Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Fossilized Gastropod (Snail)
Class Gastropoda (internal mold or 'steinkern')
sedimentary
Black Marble with Quartz Veining
Metamorphosed Limestone (Recrystallized CaCO3)
metamorphic
Sandstone (with carbonaceous plant fragments)
Arenite (composed primarily of SiO2)
sedimentary
Green Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
sedimentary
Opalite
Synthetic Opalised Glass
Mineral (Synthetic / Man-made)
Graphite
Graphite (Carbon, C)
Mineral
Pyrite
Iron Pyrite (FeS2)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Basaltic Tuff / Volcanic Breccia
Pyroclastic Breccia / Lithic Tuff
igneous
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
sedimentary
Zebra Marble
Metamorphosed Alabaster/Limestone (CaCO3)
metamorphic
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
mineral
Ironstone Concretion (Limonite/Hematite Nodules)
Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)
sedimentary
Ambergris
Physeter macrocephalus excreta (Ambergris)
mineraloid / organic geological find
Chert (with Quartz vein)
Chert (Silicon Dioxide, SiO2)
sedimentary
Pyrite
Pyrite (Iron Disulfide), FeS2
Mineral
Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Metamorphic Rock
Wood Beads (Palmwood/Ebony)
Various species for wood, but often refers to woods like Palmwood (e.g., Borassus flabellifer) or Ebony (Diospyros spp.) for their distinctive grain and hardness.
Organic Gem Material (Botanical)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Mother of Pearl (Nacre)
Calcium Carbonate (primarily aragonite, with conchiolin)
Organic Gemstone/Biomineral
Amber (Copal)
Organic gemstone, fossilized tree resin (often immature amber or copal)
Mineral
Shale
Shale (clastic sedimentary rock)
Sedimentary
Petrified Wood
Silicified wood (primarily SiO2)
sedimentary
Graphite-veined Quartzite
Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)
metamorphic
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Sedimentary Rock
Popcorn
Zea mays everta (P. Wilson) (Botanical name for the corn variety)
Organic/Biogenic
Red Jasper (beads)
SiO₂ (Silicon Dioxide)
Mineral, variety of chalcedony (microcrystalline quartz)