Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
mineral
Category
Sedimentary Or Metamorphic Derived
Browse sedimentary or metamorphic derived specimens identified by the Rock Identifier community.
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Anthracite Coal
Anthracite (Carbon Content: 86%-97%)
metamorphic
Amethyst and Calcite collection
Silicon Dioxide (SiO2) and Calcium Carbonate (CaCO3)
mineral
Ruby in Zoisite
Zoisite with Corundum (Ca2Al3(SiO4)(Si2O7)O(OH) + Al2O3)
metamorphic
Red Jasper (Quartzite)
Silicon Dioxide (SiO2) with iron oxide inclusions
mineral
Hematite
Iron(III) oxide (Fe2O3)
mineral
Orthoclase Feldspar
Potassium aluminum silicate (KAlSi3O8)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Mica Schist
Mica Schist (Composition typically contains Muscovite: KAl2(AlSi3O10)(OH)2 or Biotite: K(Mg,Fe)3AlSi3O10(OH)2 along with Quartz and Feldspar)
metamorphic
Ruby in Zoisite
Anyolite (composite of Corundum Al2O3 and Zoisite Ca2Al3(SiO4)(Si2O7)O(OH))
metamorphic
Mica Schist
Schist (Muscovite/Biotite Schist)
metamorphic
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Green Aventurine
Silicon Dioxide (Quartz) with inclusions of Fuchsite mica (K(Al,Cr)2(AlSi3O10)(OH)2)
metamorphic
Greenschist / Migmatite
Regional Metamorphic Complex (Facies: Greenschist to Amphibolite)
metamorphic
Mica Schist with Quartz
Crystalline Schist (SiO2 + KAl2(AlSi3O10)(OH)2)
metamorphic
Mica Schist (with Garnet)
Garnet-Mica Schist
metamorphic
Mixed mineral and rock collection
Predominantly quartz varieties, including amethyst, plus likely calcite, feldspar, mica, and miscellaneous polished stones
mineral
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)
mineral
Almandine Garnet
Almandine, Fe3Al2(SiO4)3
mineral
Aquamarine
Beryl (Be3Al2Si6O18)
gemstone
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2)
metamorphic
Blue Apatite
Apatite - Ca5(PO4)3(F,Cl,OH)
mineral
Weathered quartzite cobble
Quartzite, predominantly crystalline SiO₂
metamorphic
Clear Quartz Sphere
Quartz (Silicon Dioxide, SiO2)
mineral
Mica Schist
Mica Schist (primarily Muscovite or Biotite)
metamorphic
White Agate / Chalcedony
Silicon Dioxide (SiO2)
gemstone
Mica Schist
Mica Schist (primarily Muscovite or Biotite-rich sequence)
metamorphic
Light-colored pebble, likely quartzite or weathered limestone
Indeterminate from image; possible quartzite (microcrystalline SiO₂)
metamorphic
Mica Schist with Quartz
Schist containing Muscovite and Quartz
metamorphic
Yellow Jasper
Jasper (Silica-rich Microcrystalline Quartz, SiO2)
sedimentary
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
mineral
Muscovite Mica
Muscovite - KAl2(AlSi3O10)(OH)2
mineral
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
mineral
Blue Kyanite
Kyanite (Al2SiO5)
mineral
Limonite or Goethite (Ironstone)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
mineral
Schist
Chlorite/Mica Schist
metamorphic
Small red-brown mineral or rock fragment
Unidentified; possibly iron-oxide-rich jasper, garnet, or weathered sulfide
mineral
Green Aventurine
Quartzite (Silicon Dioxide, SiO2 + Fuchsite)
metamorphic
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Gneiss
Gneiss
metamorphic
![Fossilized bone fragment (probable mammalian tooth or bone) (Mineralized bone, commonly hydroxyapatite [Ca5(PO4)3(OH)] replaced or impregnated by silica/calcite) — fossil](https://media.rock.id/fossilized-bone-fragment-probable-6435bbec-570b-407e-9c9f-870b904b8d23-thumbnail.jpg)
Fossilized bone fragment (probable mammalian tooth or bone)
Mineralized bone, commonly hydroxyapatite [Ca5(PO4)3(OH)] replaced or impregnated by silica/calcite
fossil
Small white mineral fragment
Likely quartz (SiO₂), possibly calcite (CaCO₃)
mineral