Black Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Category
Man Made Material
Browse man made material specimens identified by the Rock Identifier community.
Learn about Man Made Material in the encyclopedia
View all →
Greenstone / Greenschist
Greenschist (composed of Chlorite, Epidote, and Actinolite)
metamorphic
Chert (Flint/Novaculite)
Microcrystalline Quartz (SiO2)
sedimentary
Polished orbicular jasper / brecciated jasper
Jasper, microcrystalline quartz (SiO₂), with iron-oxide and clay-rich inclusions
sedimentary
Chert (specifically Flint or Dark Chalcedony)
Silicon Dioxide (SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Red Sandstone
Arenite (typically with iron oxide/hematite cement)
sedimentary
Quartz (Small fragments)
Silicon Dioxide (SiO2)
mineral
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Dark green metamorphic rock, likely serpentinite
Serpentinite, composed mainly of serpentine-group minerals (antigorite, lizardite, or chrysotile), commonly with magnetite and minor chlorite/talc
metamorphic
Rose Quartz with Schist Matrix
Silicon Dioxide (SiO2) with Mica-Schist
mineral
Quartz-rich breccia or altered granite fragment
Polymineralic quartz–feldspar rock, likely hydrothermally altered granite/pegmatite
igneous
Tumbled green stone, likely serpentine
Serpentinite; principally serpentine-group minerals, Mg₃Si₂O₅(OH)₄
metamorphic
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Garnet Beads
Garnet Group (complex nesosilicates, e.g., Almandine Fe3Al2(SiO4)3)
Mineral
Chalcedony
Silicon Dioxide (SiO2)
mineral
Chalcedony
Silicon Dioxide (SiO2)
mineral
Likely purple quartzite or purple chert
Quartzite/chert, predominantly microcrystalline SiO₂; exact identification requires testing
metamorphic
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (Red Sandstone)
Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide)
sedimentary
Small seashell fossil or shell fragment
Likely calcium-carbonate shell material, chiefly aragonite or calcite; exact species indeterminate
fossil
Red Sandstone (Old Red Sandstone)
Ferruginous Sandstone (SiO2 + Fe2O3)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Rough Diamond
Diamond (Native Carbon, C)
mineral
Banded sandstone pebble
Quartz-rich sandstone, likely with a contrasting siltstone or fine-grained sandstone band
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Sandstone Pebble
Arenite (primarily SiO2)
sedimentary
Granite
Phaneritic plutonic rock (SiO2 rich)
igneous
Quartz-bearing granite or gneiss fragment
Granite/gneiss composed mainly of quartz (SiO₂), feldspar, and minor mica or ferromagnesian minerals
igneous
Granite Cobble
Phaneritic Felsic Igneous Rock (Granite)
igneous
Chert breccia
Sedimentary Breccia (Microcrystalline Quartz)
sedimentary
Rose quartz beads
Quartz, silicon dioxide (SiO₂), pink variety
mineral
Jasper
Silicon dioxide (SiO2) with iron impurities
sedimentary
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Polished orbicular jasper
Jasper, a microcrystalline variety of quartz (SiO₂), colored by iron oxides and other accessory minerals
igneous
Tumbled yellow quartz (likely citrine or iron-stained quartz)
Quartz, SiO₂; yellow color from trace iron or irradiation/heat-related coloration
mineral
Sandstone
Sandstone (various mineral compositions)
Sedimentary