Specular Hematite (Specularite)
Iron(III) oxide (Fe2O3)
mineral
Category
Sedimentary Rock (Specifically A Concretion Or Possibly A Geode)
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Amethyst
Silicon Dioxide (SiO2) with trace Iron impurities
mineral
Amethyst (Tumbled)
Silicon Dioxide (SiO2) with iron impurities
mineral
Amethyst
Amethyst (SiO2 with Iron impurities)
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Dragon Vein Agate
Chalcedony (Quartz) - SiO2
mineral
Gneiss (specifically a Granitic Gneiss specimen)
Gneiss (high-grade metamorphic rock primarily composed of Quartz, Feldspar, and Biotite/Amphibole)
metamorphic
Basalt (River Pebble)
Mafic volcanic rock (primarily Plagioclase feldspar and Pyroxene)
igneous
Yellow Jasper
Silicon Dioxide (SiO2) with Iron inclusions
sedimentary
Green Quartzite (with Fuchsite)
Quartzite with Muscovite variety Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
metamorphic
Banded Agate
Cryptocrystalline Quartz (SiO2)
mineral
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Fossilized Angel Wing Shell
Cyrtopleura costata
sedimentary
Green Apophyllite and Stilbite on Quartz Cluster
Apophyllite-(K) (KCa4(Si8O20)(F,OH)·8H2O), Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O), Quartz (SiO2)
Mineral
Chert (specifically Yellow/Brown Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Ironstone Concretion / Limonite Node
Goethite and Limonite (FeO(OH) nH2O)
sedimentary
Ironstone Nodule (Ironstone Concretion)
Siderite-rich Mudstone (FeCO3) or Limonite (FeO(OH)·nH2O)
sedimentary
Ironstone Concretion (Moqui Marble)
Iron Oxide Concretion (Goethite and Hematite around a Sandstone core)
sedimentary
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Conglomerate
Conglomerate (Rock composed predominantly of rounded clasts > 2mm)
sedimentary
Basalt (Purple-tinted scoria/vesicular variety)
Extrusive mafic igneous rock (SiO2 range 45–52%)
igneous
Vesicular Basalt (Scoria)
Basalt (Vesicular)
igneous
Red Jasper (possibly Brecciated Jasper or Bloodstone variety)
Jasper (Silicon Dioxide, SiO2)
sedimentary
Quartz (Milky/Vein Quartz)
Silicon Dioxide (SiO2)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Chert (or Flint)
Silicon dioxide (SiO2)
sedimentary
Pink Granite
Phaneritic Felsic Igneous Rock (Granite)
igneous
Red Jasper
Silicon dioxide (SiO2) with iron oxide (Hematite) inclusions
sedimentary
Quartzite (River Pebble)
Metamorphic Quartzite (SiO2)
metamorphic
Chert (specifically Iron-stained River Cobble)
Silicon Dioxide (SiO2)
sedimentary
Pink Granite
Phaneritic Felsic Igneous Rock (Rich in K-Feldspar)
igneous
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Red Jasper (possibly Petrified Wood)
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary (secondary formation)
Botryoidal Agate / Chalcedony Geode
Silicon Dioxide (SiO2)
mineral
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Carnelian
Carnelian Chalcedony (SiO2 with Iron Oxide impurities)
mineral
Magnetite / Iron-Rich Concretion
Magnetite (Fe3O4) or Bog Iron Limonite
mineral
Green Jasper
Jasper (variety of Microcrystalline Quartz, SiO2)
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) with iron inclusions
sedimentary
Quartzite with Quartz Geode / Vug
Crystalline Silicon Dioxide (SiO2) in Metamorphic Host
metamorphic
Amethyst Quartz (Tumbled)
Amethyst (Silicon Dioxide with iron impurities, SiO2)
mineral
Gneiss (Metamorphic Cobble)
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic