Limonite
Limonite (Hydrated iron oxide mixture, FeO(OH)·nH2O)
mineral
Category
Man Made Material (Simulated Mineral)
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Cubic Zirconia
Zirconium dioxide (ZrO2)
mineral
Banded Calcite (often sold as Mexican Onyx or Aragonite)
Calcite/Aragonite (Calcium Carbonate, CaCO3)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Bull Quartz (White Quartz)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Jasper
Silicon Dioxide (SiO2)
mineral
Fossilized Bone
Permineralized Vertebrate Bone
fossil
Fossil Snail
Gastropoda (fossilized)
fossil
Tumbled green aventurine (probable)
Quartzite dominated by quartz (SiO₂), with green mica/fuchsite or chlorite inclusions
mineral
Limonite (Iron Ore Congcretion)
Limonite (a mixture of hydrated iron(III) oxide-hydroxides, FeO(OH)·nH2O)
mineral
Greenstone / Epidosite
Epidosite (Metasomatic rock consisting mainly of Epidite Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH) and Quartz)
metamorphic
Sea Shell Fragment (Calcium Carbonate)
Aragonite / Calcite (CaCO3)
mineral
Pale blue-gray quartz-rich pebble (tentative)
Quartz, SiO₂, possibly chalcedony or a weathered metamorphic fragment
mineral
Tumbled serpentine (likely)
Serpentine-group minerals, commonly lizardite or antigorite; approximate composition Mg₃Si₂O₅(OH)₄
mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Milky quartz–rich rock
Quartz (SiO₂), likely massive milky quartz with minor dark inclusions
mineral
Sandstone
Clastic Sedimentary Rock
sedimentary
Sandstone
Arenite (SiO2 principal composition)
sedimentary
Sandstone
Arenite
sedimentary
Sandstone
Arenite
sedimentary
Petrified Wood and Mixed Rocks
Silicified Wood (SiO2)
fossil
Limonite with Trace Fossils
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
sedimentary
Limonite (Ironstone Concretion)
Limonite (FeO(OH)·nH2O)
mineral/sedimentary
Smoky quartz (likely)
Quartz, silicon dioxide (SiO₂), naturally irradiated variety
mineral
Small purple quartz crystal, likely amethyst
Amethyst: violet variety of quartz, silicon dioxide (SiO₂)
gemstone
Laterite (Iron-rich bauxite or Gossan)
Ferricrete (Fe2O3·nH2O)
sedimentary
Peridot in Matrix
Olivine ((Mg,Fe)2SiO4)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz vein in dark host rock
Quartz (SiO₂), likely in basalt, gabbro, or altered mafic rock
mineral
Polished orbicular granite
Granite, chiefly quartz, alkali feldspar, plagioclase, and biotite/amphibole
igneous
Milky quartz pebble
Quartz (silicon dioxide, SiO₂)
mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Granite (Unakite / Feldspar-rich Granite)
Granite (composed of Potassium Feldspar, Quartz, and Biotite/Epidote)
igneous
Iron-rich laterite or limonite/goethite-bearing rock
Hydrated iron oxides, chiefly goethite (α-FeO(OH)) and limonite (FeO(OH)·nH₂O), likely in a lateritic matrix
mineral
Prase Quartz on Feldspar
Quartz (Silicon Dioxide, SiO2) with Hedenbergite inclusions on Potassium Feldspar (KAlSi3O8)
mineral
Tumbled pale green aventurine (probable)
Quartz, SiO₂, with dispersed fuchsite or other green inclusions
mineral
Limonite (Iron Ore)
Limonite (mixture of hydrated iron(III) oxide-hydroxides)
Mineral