Yellow Quartz Pebble
Silicon Dioxide (SiO2)
Category
Browse sedimentary like (industrial composite) specimens identified by the Rock Identifier community.
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
Graywacke
Graywacke
Green Fluorite
Fluorite (Calcium Fluoride - CaF2)
Jasper (specifically Red Jasper or Iron-stained Chert)
Silicon dioxide (SiO2) with iron oxide inclusions
Fossilized leaf or plant impression in shale
Carbonized/impressed plant fossil, likely in fine-grained shale or mudstone; exact taxon indeterminate from the image
Limestone
Limestone (primarily composed of Calcium Carbonate, CaCO3)
Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
Anthracite Coal
Anthracite
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Coal (Anthracite or Bituminous)
Carbon (C) with varying hydrocarbon and mineral impurities
Chert (specifically Flint or Common Opal variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Ferruginous Sandstone
Ferruginous Clastic Sedimentary Rock
Chert (containing Flint nodules)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Bauxite
Bauxite (Al2O3·2H2O)
Fossilized Shell Fragment / Mother of Pearl
Calcium Carbonate (CaCO3) - Aragonite/Calcite biomineral
Fluorite
Calcium fluoride (CaF2)
Quartz (Clear Quartz)
Silicon Dioxide (SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Anthracite Coal
Anthracite
Jasper
Jasper / Silicon Dioxide (SiO₂)
Garnet Schist
Almandine-bearing Mica Schist
Rough amber-like brown mineral specimen
Uncertain from photograph; possibly iron-stained quartz, common opal, or resinous amber
Limestone
Calcium Carbonate (CaCO3)
Tumbled red jasper (likely dyed)
Jasper, microcrystalline quartz/chalcedony (SiO₂), colored by iron oxides; possibly dyed
Granite
Granite (a plutonic igneous rock)
Ironstone (Limonitic Sandstone)
Ferruginous Sandstone (rich in Limonite: FeO(OH)·nH2O)
Ferruginous Sandstone (Gozzan-like)
Ferruginous Sandstone (SiO2 with FeO(OH) inclusions)
Botryoidal Chalcedony (Agate)
Silicon Dioxide (SiO2)
Quartz Geode
Crystalline Quartz (SiO2) within a sedimentary or volcanic host
Chert (Jasper)
Silicon Dioxide (SiO2)
Polished fossilized wood (likely petrified wood)
Silicified wood; commonly quartz (SiO₂) replacing wood tissue
Sandstone Cobble with Iron Staining
Arenite with Limonite/Hematite staining
Bauxite
Bauxite (Al2O3·nH2O)
Banded Iron Formation (BIF)
Banded Iron Formation (Magnetite-Hematite-Chert)
Red Sandstone
Clastic Sandstone (typically Quartz-rich with Iron Oxide)
Chert (specifically Flint or Gray Chalcedony)
Microcrystalline Quartz (SiO2)
Chalcedony (Agate)
Cryptocrystalline Quartz (SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Bauxite
Bauxite (mainly Al(OH)3, AlO(OH))
Orange Calcite with Siderite/Iron Oxide Coating
Calcium Carbonate (CaCO3)
Chert (Flint)
Chert (Cryptocrystalline Quartz, SiO2)
Biotite Schist
Biotite-bearing Schist (K(Mg,Fe)3AlSi3O10(F,OH)2)