Raw graphite-rich metamorphic rock (probable graphite schist)
Graphite schist; predominantly crystalline carbon (graphite, C) with mica and quartz
Category
Browse sedimentary (chemically precipitated) or metamorphic specimens identified by the Rock Identifier community.
Raw graphite-rich metamorphic rock (probable graphite schist)
Graphite schist; predominantly crystalline carbon (graphite, C) with mica and quartz
Chert Pebble
Microcrystalline Quartz (SiO2)
Banded limestone or marble
Calcite-rich carbonate rock; likely veined limestone, possibly low-grade marble (CaCO₃)
Chert / Jasper
Silicon Dioxide (SiO2)
Quartz pebble
Silicon Dioxide (SiO2)
Flint
SiO2 (Microcrystalline Quartz / Chert)
Chalcedony (Agate/Chert)
Silicon Dioxide (SiO2)
Banded Calcite (Green Onyx)
Calcite (CaCO3)
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
Chalcedony (Agate/Chert variety)
Silicon Dioxide (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Weathered quartz-rich pebble
Likely milky quartz (SiO₂), possibly a quartz-rich vein fragment
Limestone
Sedimentary rock composed mainly of calcite (CaCO3)
Likely milky quartz pebble
Quartz (silicon dioxide, SiO₂)
Orange Calcite
Calcium Carbonate (CaCO3)
Limonite pseudo-concretion (Ironstone)
Limonite (FeO(OH)·nH2O) / Goethite
Banded Calcite (Mexican Onyx)
Calcium Carbonate (CaCO3)
Limonite Concretion
Hydrated Iron Oxide-Hydroxide, FeO(OH)·nH2O
Hematite
Iron(III) oxide (Fe2O3)
Quartz Pebble
Silicon Dioxide (SiO2)
Blue Apatite
Calcium phosphate mineral, Ca5(PO4)3(F,Cl,OH)
Likely iron-rich metamorphic rock (possibly hematite-rich ironstone)
Uncertain from the image; possible hematite-bearing ironstone, chiefly Fe₂O₃ with associated silicate minerals
Chert (Arrowhead artifact)
Chert (Cryptocrystalline Silica, SiO2)
Quartz
SiO2 (Silicon Dioxide)
Quartz pebble with a conchoidal chip
Silicon dioxide (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Yellow Quartz
Silicon Dioxide (SiO2)
Limonite (Ironstone Concretion)
Limonite (Hydrous ferric oxide mixture, FeO(OH)·nH2O)
Black Chert River Stone
Cryptocrystalline Quartz (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert (Chalcedony)
Silicon Dioxide (SiO2)
Fairy Stone (Menilite Concretion)
Carbonate-rich concretion (often Siderite or Calcite in Clay)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (River Pebble with Liesegang Rings)
Microcrystalline Silicon Dioxide (SiO2)
Quartz Crystal
Silicon Dioxide (SiO2)
Chert (with Quartz Veining)
Microcrystalline Quartz (SiO2)
Honey Calcite
Calcium Carbonate (CaCO3)
Sandstone with Liesegang Rings
Arenite with Iron Oxide Concretions
Red Jasper Pebble
Opaque microcrystalline Quartz (SiO2) with Iron Oxide
Goethite/Hematite Nodule
Goethite (FeO(OH)) and Hematite (Fe2O3)
Red Jasper
Microcrystalline Quartz (Chalcedony), SiO2