Rhodonite
Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3
Category
Browse metamorphic or sedimentary depending on local grade specimens identified by the Rock Identifier community.
Rhodonite
Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3
Quartz (Chert/Chunky Chalcedony)
Silicon Dioxide (SiO2)
Amber (Cherry or Red variety)
Succinite (with various trace amounts of organic compounds)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Grey Chalcedony
Silicon Dioxide (SiO2)
Amethyst
Quartz (Silicon Dioxide with iron impurities), SiO2
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Quartz Geode
Silicon Dioxide (SiO2)
Colorless Quartz (Rhinestone)
Silicon Dioxide (SiO2)
Quartz (Pale Rose or Milky Variety)
Silicon Dioxide (SiO2)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Quartz (Milky Variant)
Silicon Dioxide (SiO2)
Magnetite (Lodestone variety)
Magnetite (Fe3O4)
Quartz or possibly Jasper/Chert. Looks like a tumbled or water-worn stone.
SiO2 (Silicon Dioxide)
Green Jasper
Silicon Dioxide (SiO2) with impurities
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Orange Calcite
Calcium Carbonate (CaCO3)
Quartz
Silicon Dioxide (SiO2)
Magnetite / Hematite rich ore
Magnetite (Fe3O4) or Hematite (Fe2O3)
Ironstone (Limonitic Sandstone)
Ferruginous Sandstone (rich in Limonite: FeO(OH)·nH2O)
Bog Iron (Limonite)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Charoite
Charoite (Hydrated silicate of potassium, sodium, calcium, barium and strontium): (K,Sr,Ba)(Na,Ca)2[Si4O10](OH,f)·H2O
Yellow Calcite
Calcium Carbonate (CaCO3)
Blue Chalcedony
Silicon Dioxide (SiO2)
Iceland Spar (Optical Calcite)
Calcite (Calcium Carbonate, CaCO3)
Druzy Quartz (on Quartzite or Chert)
Silicon Dioxide (SiO2)
Anthracite Coal
Anthracite (Carbon)
Sandstone with Iron Oxide
Arenite (SiO2 with Fe2O3 inclusions)
Ironstone Nodules / Siderite Concretion
Siderite (FeCO3) / Ferruginous Septarian Concretion
Ironstone Concretion (Limonite/Goethite)
Goethite-rich Concretion (FeO(OH))
Conglomerate
Clastic Conglomerate (Lithic-rich)
Anthracite Coal
Anthracite coal (High-rank coal)
Ferruginous Sandstone (Ironstone)
Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))
Ironstone Concretion
Siderite or Ferruginous Concretion (FeCO3 or Iron Oxides)
Red Jasper
Silica (Silicon Dioxide, SiO2) with iron oxide inclusions
Chert (varieties: Flint, Jasper)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Chert (Chocolate or Brown Flint)
Chert (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Jasper and Quartz conglomerate (River Rock)
Silicon Dioxide (SiO2) - Chalcedony and Quartz variety
Shiva Lingam
Cryptocrystalline Quartz (Jasper) with Iron Oxide inclusions
Brown Chert
Cryptocrystalline Silica (SiO2)