Quartz fragment
Silicon Dioxide (SiO2)
Category
Browse sedimentary (chemically precipitated mineral) specimens identified by the Rock Identifier community.
Quartz fragment
Silicon Dioxide (SiO2)
Light-colored limestone
Calcite-rich limestone (CaCO₃)
Chert (Flint / Jasper / Hornstone)
Microcrystalline Quartz (SiO2)
Quartz vein rock (milky quartz)
Milky quartz, SiO₂; likely quartz-rich vein material in altered host rock
Limonite pseudo-concretion (Ironstone)
Limonite (FeO(OH)·nH2O) / Goethite
Gold Ore
Native Gold (Au)
Sandstone with Quartz Vein
Quartz-veined Arenite (SiO2 in detrital quartz matrix)
Pale limestone
Limestone, predominantly calcite (CaCO₃)
Likely red jasper or iron-rich chert
Microcrystalline quartz (SiO₂) colored by hematite/goethite
Weathered iron-rich chert or jasper
Microcrystalline quartz (SiO₂), variably stained by iron oxides
Limonite (Iron Ore)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Chalky limestone fragment
Micritic limestone, chiefly calcite (CaCO₃)
Quartz (Milky/Crystalline fragment)
Silicon Dioxide (SiO2)
Weathered iron-rich rock, possibly hematite-bearing basalt or ironstone
Uncertain; likely Fe-oxide-rich basalt/ironstone containing hematite (Fe₂O₃), magnetite (Fe₃O₄), and silicate minerals
Hematite
Hematite, Iron(III) oxide (Fe2O3)
Orange Calcite
Calcium Carbonate (CaCO3)
Red jasper (likely iron-rich chert)
Microcrystalline quartz, SiO₂, colored mainly by hematite/goethite
Chert
Chert (SiO2)
Red sandstone or iron-stained chert
Likely quartz-rich sandstone (SiO₂) or microcrystalline quartz/chert with hematite
Goethite/Hematite Nodule
Goethite (FeO(OH)) and Hematite (Fe2O3)
Green Calcite
Calcium Carbonate (CaCO3)
Limonite Concretion
Hydrated Iron Oxide-Hydroxide, FeO(OH)·nH2O
Honey Calcite
Calcium Carbonate (CaCO3)
Yellow Calcite
Calcium Carbonate (CaCO3)
Orange Calcite
Calcium Carbonate (CaCO3)
Chert (Nodular Chert)
Microcrystalline Quartz (SiO2)
Limonite (Iron Ore)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Manganese Ore (Psilomelane/Pyrolusite)
Psilomelane ((Ba,H2O)2Mn5O10) and Pyrolusite (MnO2)
Wonderstone Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Limonite (Iron Ore)
Goethite and related iron hydroxides (FeO(OH)·nH2O)
Orange Calcite
Calcium Carbonate (CaCO3)
Rhodochrosite
Manganese Carbonate (MnCO3)
Geode
Quartz / Chalcedony (SiO2)
Quartz Geode
Silicon dioxide (SiO2)
Limonite on Sandstone
Iron Oxyhydroxide (FeO(OH)·nH2O) on Quartz Sandstone
Banded Calcite / Onyx Marble
Calcite (Travertine / Onyx Marble, CaCO3)
Honey Calcite
Calcium Carbonate (CaCO3)
Hematite
Iron(III) oxide (Fe2O3)
Chert with Quartz Veining
Microcrystalline Silica (SiO2)
Chalcedony with Druzy Quartz
Silicon Dioxide (SiO2)
Fairy Stone (Menilite Concretion)
Carbonate-rich concretion (often Siderite or Calcite in Clay)
Orange Calcite
Calcium Carbonate (CaCO3)