Marble
Metamorphosed Limestone (main mineral: Calcite, CaCO3)
Category
Browse sedimentary (chemically precipitated mineral) specimens identified by the Rock Identifier community.
Marble
Metamorphosed Limestone (main mineral: Calcite, CaCO3)
Fluorite (Purple Fluorite in Matrix)
Fluorite (Calcium Fluoride, CaF2)
Chert (Flint)
Chert (microcrystalline quartz)
Sunstone
Aventurine Feldspar (composition: (Ca,Na)((Al,Si)2Si2O8))
Milky Quartz (Water-worn Pebble)
Quartz (Silicon Dioxide, SiO2)
Black Obsidian
Volcanic Glass (predominantly SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Banded Agate
Chalcedony (Silicon Dioxide, SiO2)
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe)
Chert (Jasper variation)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Epidote (or Epidote-rich rock)
Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).
Mahogany Obsidian
Obsidian (Volcanic Glass) with Hematite or Magnetite inclusions, SiO2 (Silicon Dioxide)
Amethyst Geode
Amethyst (Silicon Dioxide), Formula: SiO2
Quartz with Chalcopyrite and Pyrite
Silicon Dioxide (SiO2) with Copper Iron Sulfide (CuFeS2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Dyed Agate
Silicon Dioxide with artificial pigment (SiO2)
Quartz / Quartzite Fragment
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz (Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)
Chert (specifically a stream-worn Chert Nodule)
Sedimentary Cryptocrystalline Quartz (SiO2)
Chert (Flint Pebbles)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Banded Chert
Silicon Dioxide (SiO2)
Chert (with Quartz vein)
Chert (Silicon Dioxide, SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (likely Milky Quartz or Chalcedony)
Quartz (SiO2 - Silicon Dioxide)
Chert (Chert / Flint nodule)
Silicon Dioxide (SiO2)
Diabase (Greenstone)
Diabase (also known as Dolerite)
Kyanite
Kyanite (Al2SiO5)
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Calcite
Calcite (CaCO₃, Calcium Carbonate)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Chert (Jasper)
Silicon dioxide (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Fluorite (likely Fluorite on Quartz/Matrix)
Calcium Fluoride (CaF2)
Amethyst on Agate/Basalt Matrix
Silicon Dioxide (SiO2) with iron impurities
Quartz (Milky or Cloudy Quartz)
Quartz (Silicon Dioxide, SiO2)
Banded Chert
Sedimentary Cryptocrystalline Quartz (SiO2)
Chert / Flint (a variety of Chert)
Chert (SiO2)
Vesicular Basalt
Amygdaloidal Basalt (Mafic extrusive volcanic rock)
Ferruginous Sandstone (Ironstone Nodules)
Ferruginous Quartz-Arenite (with Goethite/Hematite cement)
Desert Varnish (on Sandstone)
Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)