Limonite-stained Gossan/Ironstone
Goethite and Hematite (Fe2O3 • nH2O)
sedimentary
Category
Not A Geological Specimen
Browse not a geological specimen specimens identified by the Rock Identifier community.
Learn about Not A Geological Specimen in the encyclopedia
View all →
Yellow Jasper
Silicon Dioxide (SiO2) with impure Iron inclusions
sedimentary
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
sedimentary
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Pink Granite (Water-worn Cobble)
Phaneritic Felsic Intrusive Igneous Rock
igneous
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Chert (variations include Chalcedony and Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Granite Cobble
Granite (Phaneritic Quartz-Feldspar Felsic Rock)
igneous
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Quartz in Host Rock
Silicon Dioxide (SiO2) in Rhyolite or Granite matrix
igneous
Quartz (in a rock matrix)
Quartz (SiO2)
mineral
Granite Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
mineral
Diorite (Salt and Pepper Rock)
Phaneritic Plutonic Diorite; chemical composition roughly 52-63% silica (SiO2)
igneous
Gossan (Limonite/Goethite)
Hydrated iron oxides (primarily FeO(OH)·nH2O)
mineral
Chalcopyrite
Chalcopyrite (CuFeS2)
mineral
Quartz with Pyrite
Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Brecciated Chert
Brecciated Chert (Microcrystalline Quartz, SiO2)
sedimentary
White Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Granite (Pink/Red)
Phaneritic Igneous Rock (Rich in K-Feldspar)
igneous
Quartz (River Pebble)
Quartz (Silicon Dioxide, SiO2)
mineral
Granite
Phaneritic intrusive igneous rock (approx. 70 percent SiO2)
igneous
Siltstone
Siltstone (primarily composed of microcrystalline Quartz and Feldspar)
sedimentary
Chert Breccia (Yellow Jasper)
Silicon Dioxide (SiO2) - Brecciated Chert
sedimentary
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Calcite
Calcium Carbonate (CaCO3)
mineral
Jasper (Tiger Eye variety transition)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Biotite (Black Mica)
Biotite - K(Mg,Fe)3(AlSi3O10)(OH)2
mineral
Fluorite (Green Fluorite)
Fluorite (Calcium Fluoride, CaF2)
mineral
Calcite
Calcium Carbonate (CaCO3)
mineral
Sandstone (Ferruginous)
Ferruginous Sandstone (SiO2 with Fe2O3)
sedimentary
Pyrite (on host rock)
Iron Sulfide (FeS2)
mineral
Pyrite (on Quartz matrix)
Iron Sulfide (FeS2)
mineral
White Calcite (Dogtooth Spar or Crystalline Calcite)
Calcite (Calcium Carbonate, CaCO3)
mineral
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Conglomerate
Conglomerate (Sedimentary Clastic Rock)
sedimentary
Basalt (with possible iron oxide staining)
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
igneous
Milky Quartz (river pebble)
Quartz (Silicon Dioxide, SiO2)
mineral
Grey Limestone Pebble
Limestone (Calcium Carbonate - CaCO3)
sedimentary