Ironstone Concretion (Iron-rich Mudstone)
Siderite / Geothite concretion (FeCO3 / FeO(OH))
sedimentary
Category
Minerals
Browse minerals specimens identified by the Rock Identifier community.
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Sandstone (with vugs)
Arenite / Sedimentary Sandstone
sedimentary
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)
igneous
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Mineral
Milky Quartz with Iron Oxide
Quartz (Silicon Dioxide, SiO2) with Limonite/Goethite staining
mineral
Quartzite (Aventurine type)
Metamorphosed Quartz Sandstone (SiO2 with inclusions)
metamorphic
Diorite (Spotted)
Plutonic Igneous Rock (Diorite)
igneous
Diorite
Diorite (an intrusive igneous rock)
igneous
Greenschist (Chlorite Schist)
Greenschist (containing chlorite, actinolite, and epidote)
metamorphic
Granite
Granite (Felsic Plutonic Rock)
igneous
Diorite
Plutonic Igneous Rock (Intermediate Composition)
Igneous
Granite Pebble
Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Granite
Plutonic Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Malachite
Copper carbonate hydroxide, Cu2CO3(OH)2
mineral
Limonite after Pyrite (Prophecy Stone or Ironstone Concretion)
Goethite/Limonite pseudomorph after Pyrite/Marcasite (FeO(OH)·nH2O)
mineral
Yellow Ochre / Limonite
Hydrated ferric oxide (FeO(OH)·nH2O)
mineral
Diorite
Diorite
igneous
Gneiss (specifically Pink Gneiss)
Gneiss (high-grade regional metamorphic rock)
metamorphic
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
igneous
Lapis Lazuli
Lapis Lazuli (A complex rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Chrysocolla
Hydrated copper phyllosilicate mineral (Cu,Al)2H2Si2O5(OH)4·n(H2O)
mineral
Amygdaloidal Basalt
Amygdaloidal Basalt (Ca-rich Plagioclase, Pyroxene, and Olivine)
igneous
Gneiss (with Quartzite and Biotite)
Gneiss containing SiO2 (Quartz), K(Mg,Fe)3AlSi3O10(OH)2 (Biotite), and (K,Na,Ca)AlSi3O8 (Feldspar)
metamorphic
Greenstone / Greenschist
Greenschist (composed primarily of Chlorite, Epidote, and Actinolite)
metamorphic
Ferruginous Quartz
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
mineral
Yellow Quartz River Pebble
Silicon Dioxide (SiO2)
mineral
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Gold Sheen Obsidian
Volcanic Glass (SiO2 + impurities)
igneous
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
mineral
Chert (often called Jasper or Flint)
Microcrystalline Silica (SiO2)
sedimentary
Greenstone (Altered Mafic Rock)
Greenschist / Meta-basalt
metamorphic
Chert (Banded)
Microcrystalline Quartz (SiO2)
sedimentary
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Chalcedony (Agate/Carnelian variant)
Silicon Dioxide (SiO2)
mineral
Banded Agate
Cryptocrystalline Quartz (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Chert (Green Chert or Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
Sedimentary
Chert / River Jasper
Silicon Dioxide (SiO2)
sedimentary
Quartz (Chalcedony)
Silicon Dioxide (SiO2)
mineral
Dalmatian Jasper / Dalmatian Stone
Peralkaline Rock (Silicon Dioxide with Amphibole inclusions)
igneous