Moonstone (Feldspar)
Orthoclase or Oligoclase (KAlSi3O8)
Category
Browse sedimentary and metamorphic minerals specimens identified by the Rock Identifier community.
Moonstone (Feldspar)
Orthoclase or Oligoclase (KAlSi3O8)
Quartzite River Cobble
Quartzite (SiO2)
Quartzite
Quartzite (primarily SiO2)
Anthracite Coal
Anthracite (high-rank coal)
Anthracite Coal
High-rank coal (primarily Carbon, C)
Gneiss (Metamorphic Cobble)
Gneiss (High-grade Regional Metamorphic Rock)
Rhodonite
Manganese silicate (Mn,Fe,Mg,Ca)SiO3
Biotite or Phlogopite Mica
K(Mg,Fe)3(AlSi3O10)(F,OH)2
Lazulite
Lazulite (MgAl2(PO4)2(OH)2)
Septarian Nodule (Septarian Dragon Stone)
Septarian concretion (composition: Calcite CaCO3, Aragonite CaCO3, and Limestone/Clay)
Geode (unopened)
SiO2 - Chert-shelled concretion (mostly Quartz)
Mica Schist (with Golden/Biotite inclusions)
K(Mg,Fe)3AlSi3O10(F,OH)2 (Biotite), KAl2(AlSi3O10)(F,OH)2 (Muscovite)
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Silicon dioxide (SiO2) - Cryptocrystalline Quartz
Chert (variously known as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (varieties: Flint or Chalcedony)
Microcrystalline Quartz (SiO2)
Sandstone (Banded)
Clastic sedimentary rock (primarily SiO2)
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Red Sandstone (Iron-rich Sandstone)
Clastic Sedimentary Rock - Quartz Arenite / Arkose with Hematite Cement
Chert (with Lichen)
Microcrystalline Quartz (SiO2)
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Ferruginous Sandstone
Clastic sedimentary rock (primarily Quartz with Iron Oxide cement)
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
Chert (often called Flint or Jasper if reddish)
Microcrystalline Quartz (SiO2)
Chert (or Flint)
Chert (Sedimentary Cryptocrystalline Sio2)
Ferruginous Sandstone (Gritstone)
Clastic sedimentary rock with iron-rich cement (FeO(OH)·nH2O)
Conglomerate
Conglomerate (clastic sedimentary rock)
Red Jasper
Red Jasper (variety of Chalcedony, SiO₂)
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
White Marble (Industrial/Architectural)
Recrystallized Calcite (CaCO3)
Marble
Recrystallized Calcite (CaCO3)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Sandstone (Ferruginous)
Arenite (with Iron Oxides)
Red Siltstone
Siltstone (composed mainly of SiO2 and Fe2O3)
Red Sandstone (Iron-rich)
Ferruginous Sandstone (variable formula, primarily SiO2 + Fe2O3)
Red Sandstone
Sandstone (principally Quartz with Iron Oxide coating)
Montana Moss Agate
Chalcedony (SiO2) with Manganese/Iron oxide inclusions
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Moqui Marble (Ironstone Concretion)
Iron Oxide Concretion (Fe2O3 / FeO(OH))
Limonitic Sandstone (Stained Sandstone)
Clastic Sedimentary Rock with Iron Oxide (Limonite/Goethite) staining
Yellow Jasper
Silicon Dioxide (SiO2) with hydrated iron oxide impurities