Chert (Green Chert or Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Category
Anthropogenic (Man Made Material Mimicking Sedimentary Rock)
Browse anthropogenic (man made material mimicking sedimentary rock) specimens identified by the Rock Identifier community.
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Chalk
CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock
Sedimentary
Chert
Microcrystalline quartz (SiO2)
sedimentary
Coquina
Biogenic Limestone (Coquina)
sedimentary
Sandstone
Sedimentary Clastic Rock (Quartzose Sandstone)
sedimentary
Crinoid Fossil in Limestone
Crinoid columnal (Class Crinoidea) in biomicrite
fossil
Chert Arrowhead
Chert (Cryptocrystalline variety of Quartz, SiO2)
sedimentary
Chert (and/or Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Tektite
Impactite (Natural Silicate Glass)
meteorite
Coquina
Biogenic Limestone (Calcite, CaCO3)
sedimentary
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Chert
Microcrystalline quartz (SiO2)
sedimentary
Brecciated jasper (likely red-and-cream jasper)
Jasper, an opaque microcrystalline variety of quartz; primarily cryptocrystalline SiO₂ with iron-oxide staining and possible chalcedony/quartz veining
gemstone
Nephrite Jade
Nephrite
Mineral/Rock
White Marble
Recrystallized Calcite (CaCO3)
metamorphic
Weathered fossil shell fragment
Indeterminate bioclastic carbonate, likely molluscan shell (calcium carbonate, commonly aragonite or calcite)
fossil
Cardstock (Paper)
Cellulose (C6H10O5)n
sedimentary (man-made)
Polished orbicular jasper
Jasper, microcrystalline quartz (SiO₂), with iron oxides and other inclusions
mineral
Chert / Flint
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint)
Chert (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Vesicular basalt (likely scoria)
Basaltic scoria; predominantly plagioclase, pyroxene, and olivine in a mafic volcanic glass/microcrystalline matrix
igneous
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Riverstone (Sandstone Pebble)
Arenite (SiO2 with various lithic fragments)
sedimentary
Jasper (Iron-rich Chalcedony)
Jasper (Microcrystalline Silicon Dioxide, SiO2 plus iron oxide impurities)
Sedimentary / Metamorphic
Small metallic-looking mineral/rock fragment
Indeterminate from image; possibly galena, hematite, or metallic slag
mineral
Quartz (Microcrystalline/Chert)
Silicon Dioxide (SiO2)
mineral
Polymictic breccia, possibly volcanic breccia
Polymictic clastic breccia; likely a matrix-supported breccia containing lithic fragments, quartz, feldspar, and dark mafic minerals
sedimentary
Sandstone Pebble
Sandstone (primarily SiO2)
sedimentary
Chert (Jasper type)
Microcrystalline Quartz (SiO2)
sedimentary
Colorless faceted quartz-like gemstone
Likely quartz (SiO₂), though the appearance may also indicate man-made glass or cubic zirconia
gemstone
Sandstone
Arenite (SiO2 dominant)
sedimentary
Chert (with nodule)
Microcrystalline Quartz (SiO2)
sedimentary
Chert
Microcrystalline Silicon Dioxide (SiO2)
sedimentary
Blue Goldstone
Synthetic glass with copper or cobalt/manganese inclusions
man-made glass
Tumbled greenstone / serpentinite (probable)
Serpentinite, chiefly Mg-rich serpentine minerals (antigorite, lizardite, chrysotile), possibly mixed with chlorite, magnetite, or carbonate
metamorphic
Chert (River Siltstone/Quartzite type)
Microcrystalline Quartz (SiO2)
sedimentary
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Chert Pebble
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Likely weathered iron-rich rock or slag fragment
Uncertain; possibly limonite/goethite-rich material (FeO(OH)·nH₂O)
mineral
Unknown dark mineral/rock fragment
Indeterminate; possibly a dark sulfide mineral or slag-like geological fragment
mineral