Industrial Byproduct (Anthropogenic Material)

Peridot

Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)

Pumice

Pumicite / Vesicular Rhyolite

Dyed Quartz (often sold as 'Blue Quartz' or 'Blue Agate')

Silicon Dioxide (SiO2) with artificial pigment

Chert (often called Flint or River Pebble)

Chert (Microcrystalline Quartz, SiO2)

Chert (Flint)

Chert (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Granite (Dioritic variant)

Granite (Phaneritic Igneous Rock)

Chert (Yellow Jasper/Quartzite Pebble)

Microcrystalline Silicon Dioxide (SiO2)

Man-made Polished Porcelain Tile (Artificial Geologic Lookalike)

Fused Silicate Ceramic with Alumina (Synthetic Kaolinite derivative)

Nephrite Jade

Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Yellow/Tan variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Granite Pebble

Granite (composed primarily of Quartz, Feldspar, and Mica)

Granite Sand (Decomposed Granite)

Grus / Quartz-Feldspar Detritus

Chert (variations include Flint/Jasper)

Cryptocrystalline Silicon Dioxide (SiO2)

Quartzite Pebble

Metamorphic Quartz (SiO2)

Chert (Red/Pink Jasper subtype)

Silicon Dioxide (SiO2)

Chert (Flint)

Chert (SiO2)

Chert (often called Flint)

Microcrystalline to cryptocrystalline quartz (SiO2)

Basalt with Secondary Mineralization (Likely Zeolites or Calcite)

Aphanitic mafic volcanic rock with secondary mineral inclusions (e.g., CaAl2Si3O10·3H2O for Scolecite)

Polished Ocean Jasper

Orbicular Jasper (variety of Chalcedony/Quartz, SiO2)

Limonite (Yellow Ochre)

FeO(OH)·nH2O (Hydrous iron(III) oxide-hydroxide mixture)

Geode (unopened)

Chert / Chalcedony Geode (SiO2)

Petrified Wood

Silicon Dioxide (SiO2) - Calcified / Silicified Wood

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)

Chert (often called Flint in this context)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Limonite (Iron Stone/Iron Ore)

FeO(OH)·nH2O (Hydrous ferric oxide)

Granite Glacial Erratic

Granite (Phaneritic Quartz-Feldspar Plutonic Rock)

Pumice

Pumice (Volcanic glass with vesicular texture)

Basalt with Quartz/Calcite Veins

Basalt (Aphanitic Mafic Igneous Rock)

Riverstone Quartzite (Iron-stained)

Quartzite (primarily SiO2 with Limonite/Goethite staining)

Pumice

Pumicite (Amorphous volcanic glass)

Granite

Phaneritic Igneous Rock (composed mostly of Quartz, Feldspar, and Mica)

Vesicular Basalt

Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Basalt

Basalt (composition predominately plagioclase feldspar and pyroxene)

Pumice

Pumice (Amorphous volcanic glass)

Iron Ore (Limonite and Hematite)

Goethite/Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)

Pumice

Pumicite

Mother of Pearl and Onyx

Aragonite (Mother of Pearl) and Chalcedony (Onyx)

Chert (Chalcedony/Agate)

Microcrystalline Quartz (SiO2)

Sandstone (with Lichen)

Arenite (composed primarily of SiO2)

Sandstone (Ferruginous)

Arenite (Fe-rich)