Limonite / Ironstone
FeO(OH)·nH2O
sedimentary
Category
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Blue Agate
Chalcedony (SiO2)
gemstone
Mica schist
Mica-rich schist, likely muscovite–quartz schist
metamorphic
Green aventurine (likely)
Quartz, SiO₂, with green fuchsite mica inclusions
mineral
Granite Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Almandine Garnet
Iron aluminum silicate - Fe3Al2(SiO4)3
metamorphic
Stromatolite (stromatolitic limestone)
Laminated microbial carbonate, chiefly calcite (CaCO₃); precise species or age cannot be determined from the photo
sedimentary
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
mineral
Fuchsite (Green Muscovite / Verdite)
Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)
metamorphic
Limonite (Iron Ore)
Limonite (Hydrous iron(III) oxide-hydroxide mixture, primarily FeO(OH)·nH2O)
mineral
Greenschist
Greenschist
metamorphic
Amethyst
Silicon Dioxide (SiO2)
mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Sunstone (Orthoclase Feldspar variant)
Orthoclase (KAlSi3O8) with inclusions
mineral
Likely quartz-rich granite or granitic pegmatite
Granite, composed chiefly of quartz (SiO₂), feldspar, and mica; identification from the image is approximate
igneous
Carnelian
Carnelian (Cryptocrystalline Quartz, SiO2)
mineral
Dalmatian Stone
Peralkaline rhyolite with arfvedsonite inclusions
igneous
Peach Moonstone
Orthoclase (KAlSi3O8)
mineral
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
mineral
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with dendritic inclusions
mineral
Concrete or asphalt-like aggregate surface with a dark fragment
Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock
sedimentary
![Arfvedsonite (often mistakenly sold as Astrophyllite) (Arfvedsonite [Na3(Fe2+)4Fe3+Si8O22(OH)2]) — mineral](https://media.rockidentification.com/6e8b521a-e0bc-4cec-8657-2fd2e3051a43-thumbnail.jpg)
Arfvedsonite (often mistakenly sold as Astrophyllite)
Arfvedsonite [Na3(Fe2+)4Fe3+Si8O22(OH)2]
mineral
Agate
Silicon dioxide (Chalcedony), SiO2
sedimentary
Green Aventurine
Quartz variant (SiO2) with Fuchsite inclusions
mineral
Carnelian (Polished Agate)
Silicon Dioxide (SiO2)
gemstone
Moonstone
Orthoclase (Potassium aluminum silicate - KAlSi3O8)
mineral
Tumbled orange chalcedony or common opal
Microcrystalline quartz (SiO₂), possibly hydrated silica opal (SiO₂·nH₂O)
mineral
Peach moonstone (polished/tumbled feldspar)
Orthoclase feldspar, KAlSi₃O₈ (possibly with albite intergrowths)
mineral
Dyed blue howlite or magnesite tumbled stone
Howlite (Ca₂B₅SiO₉(OH)₅), possibly magnesite (MgCO₃), artificially dyed blue
mineral
Dendritic Jasper
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
sedimentary
Tree Agate (also known as Dendritic Agate)
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
mineral
Barite
Barium Sulfate (BaSO4)
mineral
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
mineral
Agate
Silicon Dioxide (Chalcedony), SiO2
gemstone
Iron Ore / Hematite Rock
Iron oxide (primarily Hematite, Fe2O3)
mineral
Coral Fossil (Scleractinia)
Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)
sedimentary
Clear Quartz (Druzy/Crystal Cluster)
Silicon Dioxide (SiO2)
mineral
Hematite
Hematite (Fe2O3)
mineral
Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)
mineral
Hematite
Iron(III) oxide (Fe2O3)
mineral
Ferruginous Sandstone
Sandstone (arenite) with Limonite/Goethite cement
sedimentary
Weathered granite or granitic gneiss
Granite/granitic gneiss, composed mainly of quartz, feldspar, and mica
igneous