Banded Iron Formation (BIF) / Banded Sandstone Nodule
Hematite-rich Sandstone / Ferruginous Chert
sedimentary
Category
Synthetic Material (Not A Rock Or Mineral)
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Concrete / Anthropogenic Conglomerate
Man-made composite material (Portland cement, aggregate, and water)
not a natural rock
Sandstone / Weathered Quartzite
Sandstone (Quartz Arenite)
sedimentary
Chalky Limestone
Carbonate sedimentary rock (CaCO3)
sedimentary
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 cement)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
sedimentary
Fossil-bearing sedimentary rock, possibly fossil wood or bone
Indeterminate silicified/carbonate fossil in sandstone or mudstone
fossil
Granite (Weathered)
Course-grained Intrusive Igneous Rock
igneous
Dark-colored Igneous Rock (likely Basalt or Diabase)
Basalt (extrusive igneous) or Diabase (intrusive igneous)
Igneous Rock
Banded gneiss pebble
Gneiss, likely quartz–feldspar–mica gneiss
metamorphic
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of organic matter)
fossil
Agate
Silicon Dioxide (Chalcedony), SiO2
gemstone
Polished jasper pebble
Jasper, microcrystalline quartz (SiO₂) with iron-oxide and clay-mineral impurities
metamorphic
White quartz pebble (likely milky quartz)
Quartz, silicon dioxide (SiO₂)
mineral
Greenstone (Celadonite-bearing Volcanic)
Hydrothermally altered basalt or andesite with Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)
metamorphic
Weathered volcanic rock, likely basalt
Basalt; commonly composed of plagioclase, pyroxene, and iron-rich oxides
igneous
Iron-rich slag or limonite-bearing rock
Hydrated iron oxides, chiefly limonite/goethite (FeO(OH)·nH₂O); possibly industrial iron slag
mineral
Weathered iron-rich rock, possibly laterite or altered basalt
Probable ferruginous basalt/lat eritic material; exact identification requires testing
igneous
Slate
Metamorphic Pelitic Rock
metamorphic
Slate
Metamorphic Pelitic Rock
metamorphic
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Polished agate geode
Chalcedony (microcrystalline quartz, SiO₂) with quartz druse crystals
mineral
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Sandstone
Sandstone (Clastic Sedimentary Rock)
Sedimentary Rock
Jasper with Quartz Vein
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Coquina / Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Ironstone Concretion / Goethite-Hematite Geode
Goethite / Hematite Concretion (Fe3O4 / FeO(OH) / Fe2O3)
sedimentary
Polished red jasper
Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides
mineral
Chert / Jasper
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint)
Cryptocrystalline Quartz (SiO2)
sedimentary
Unakite
Unakite (metamorphosed granitic rock)
metamorphic
Quartz-rich metamorphic rock, likely quartzite
Quartzite; predominantly microcrystalline quartz (SiO₂), with possible mica or iron-oxide impurities
metamorphic
Fossil Coral
Rugose Coral / Hexagonaria (CaCO3)
fossil
Jasper River Stone
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Vesicular basalt (possibly scoria)
Basalt; chiefly plagioclase feldspar, pyroxene, and often olivine, with volcanic glass
igneous
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Goldstone (Red)
Aventurine Glass (SiO2 + Cu)
Synthetic Glass (Often categorized as a simulated mineral)
Porphyritic basalt (likely amygdaloidal basalt)
Basalt containing larger plagioclase crystals and pale vesicle-fill minerals, commonly calcite, zeolite, or quartz
igneous
Sandstone (Greywacke/Lithic Sandstone)
Arenite / Lithic Sandstone
sedimentary
Weathered iron-rich rock, possibly basalt or ironstone
Indeterminate; likely Fe-oxide-bearing basaltic rock (commonly magnetite/hematite in a silicate matrix)
igneous
Red jasper (likely iron-rich chert)
Microcrystalline quartz (SiO₂), colored by hematite/goethite; possibly brecciated jasper
sedimentary