Limonite or Ironstone Concretion
FeO(OH)·nH₂O (Hydrated iron oxide-hydroxide)
mineral
Category
Organic Gemstone (Sedimentary Associations)
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
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Milky quartz with iron-oxide staining and dark matrix
Quartz (SiO₂), likely with hematite/goethite and minor feldspar or mica
mineral
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
mineral
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Sodalite
Na8(Al6Si6O24)Cl2
mineral
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Paleoxylon (SiO2)
fossil
Epidote with Unakite characteristics
{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
metamorphic
Sphalerite in Matrix (Polished Point)
Zinc sulfide (Zn,Fe)S
mineral
Bog Iron (Limonite)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Sapphirine in Matrix
Sapphirine (Mg,Al)8(Al,Si)6O20
mineral
Chrysocolla with Malachite
Cu2-xAlx(H2-xSi2O5)(OH)4%CnH2O (Chrysocolla)
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Chert (specifically Flint or Novaculite variant)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Tahitian Pearl (Black / Pistachio Pearl)
Biogenic Aragonite / Calcite (CaCO3 with conchiolin)
gemstone
Amber (Raw Copal)
Fossilized Plant Resin (Gummite/Succinite)
mineral
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
sedimentary
Pearl
Nacre (aragonite, CaCO₃, in an organic conchiolin matrix)
gemstone
Fluorite-Gedrite in Quartz (Schist)
Fluorite (CaF2) with Gedrite in Quartz/Feldspar Matrix
metamorphic
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint or Jasper)
Cryptocrystalline quartz (SiO2)
sedimentary
Chert (White Chert or Flint)
Microcrystalline or cryptocrystalline quartz (SiO2)
sedimentary
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Nodule)
Chert (composition: SiO2)
sedimentary
Chert (specifically Red Chert / Jasper)
Silicon Dioxide (SiO2)
sedimentary
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides
mineral
Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin
gemstone
Laterite Gravel with Quartz
Ferruginous Laterite (Fe2O3·nH2O)
sedimentary
Red Jasper
Microcrystalline Quartz (SiO2) with iron oxide impurities
sedimentary
Chert (specifically Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chrysocolla
Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Red Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Amber
Succinite (fossilized resin)
Organic Mineraloid
Pyrite
Iron Disulfide (FeS2)
mineral
Sandstone (with Rock Art)
Sandstone (Clastic Sedimentary Rock)
sedimentary
Chrysocolla on Quartz
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) with Quartz (SiO2)
mineral
Amber
Succinite (Resinous fossilized tree sap)
Mineraloid
Chert (specifically Tan Chert or Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
sedimentary