Quartz-veined Basalt or Diabase Pebble
Igneous rock with hydrothermal quartz vein
igneous
Category
Not A Geological Specimen
Browse not a geological specimen specimens identified by the Rock Identifier community.
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Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Jasper
Silicon Dioxide (Microcrystalline Quartz), SiO2
sedimentary
Limonite (Ironstone Concretion)
Hydrous ferric oxides (FeO(OH)·nH2O)
mineral
Mica Schist with Vein
Mica Schist
metamorphic
Banded Sedimentary Rock
Sedimentary rock with Liesegang banding
sedimentary
Fossilized Coral
Anthozoa
fossil
Conglomerate (Greenstone/Pebble Conglomerate)
Polymictic Conglomerate
sedimentary
Calamites Fossil (Horsetail Stem)
Calamites (Genus), part of the class Equisetopsida
sedimentary
Polished green stone, likely serpentine or altered basalt
Serpentine-group minerals, chiefly Mg₃Si₂O₅(OH)₄; exact identification requires testing
metamorphic
Metal Alloy (Likely Pewter or Sterling Silver)
Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).
Man-made material (metal)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
fossil
Agate Geode
Silicon Dioxide (Chalcedony / Quartz), SiO2
sedimentary
Fossil Coral
Cnidaria Anthozoa (Fossilized)
sedimentary
Jasper in Quartz / Brecciated Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
mineral
Pyrite Schist
Metamorphic rock containing FeS2 (Pyrite) with mica and quartz
metamorphic
Jasper
Silicon Dioxide (Microcrystalline Quartz / Chalcedony)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
sedimentary
Fossiliferous Chert (Brachiopod/Bryozoan Fossil)
Microcrystalline quartz (SiO2) with fossil inclusions
sedimentary
Fossilized Coral
Rugose Coral / Hexagonaria (Fossilized calcium carbonate)
fossil
Rounded graywacke or sandstone cobble
Lithified clastic sandstone; likely quartz–feldspar–lithic grain aggregate in a silica or calcite matrix
sedimentary
Dog (Sleeping)
Canis familiaris (or Canis lupus familiaris)
Organic/Biological
Limonite Concretion
Goethite/Limonite concretion (FeO(OH)·nH2O)
sedimentary
Concretion
Septarian Concretion
sedimentary
Limonite (Ironstone Concretion)
Limonite: FeO(OH)·nH2O
sedimentary
Small metallic-looking mineral/rock fragment
Indeterminate from image; possibly galena, hematite, or metallic slag
mineral
Polished orbicular granite (likely orbicular diorite)
Orbicular granitoid; chiefly quartz, feldspar, and dark amphibole/biotite
igneous
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Fossil Coral
Phylum Cnidaria / Scleractinia
fossil
Quartzite Pebble with Pyrite Coating
SiO2 (Quartz) with FeS2 (Pyrite) inclusions or surface coating
metamorphic
Quartz (or Chalcedony) Specimen
Silicon Dioxide (SiO2)
mineral
Basalt Column Section
Columnar Basalt (Mafic Extrusive Igneous Rock)
igneous
Fossilized Coral (Petrified Coral)
Anthozoa (Scleractinia)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Brecciated Chert with Quartz Veining
Microcrystalline Quartz (SiO2) Breccia
sedimentary
Septarian Nodule (Septarian Stone)
Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)
sedimentary
Fossilized Favosites (Honeycomb Coral)
Favosites (extinct genus of tabulate coral)
sedimentary
Fossilized Coral
Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)
sedimentary
Banded Gneiss Pebble
Banded Gneiss
metamorphic
Pegmatite (Quartz, Feldspar, and Tourmaline/Biotite)
Pegmatitic Igneous Rock
igneous
Petrified Wood / Red Jasper
Silicified wood (primarily Silicon Dioxide, SiO2)
sedimentary
Fossilized Gastropod in Limestone
Gastropoda (Class) in Fossiliferous Limestone
sedimentary