Anthropogenic (Man Made Product Subject To Geological Processes)

Quartz River Cobble

Silicon Dioxide (SiO2)

Diamond in Kimberlite

Diamond (C in Kimberlite Matrix)

Peridot

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

Sandstone (likely Quartzose Sandstone)

Arenite

Fossiliferous Limestone (Coquina)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone

Limestone (composed primarily of calcite with included fossils CaCO3)

Note: The image provided is a fabric sock, not a geological specimen.

Polyester-Cotton Blend with Elastane

Basalt

Basalt (extrusive igneous rock)

Yellow Calcite

Calcite (Calcium Carbonate, CaCO3)

Diamond (in jewelry setting)

Carbon (C)

Pearl

Aragonite (CaCO3) with Conchiolin

Rough Citrine Quartz

Citrine (Silicon Dioxide, SiO2 with iron impurities)

Petrified Wood

Silicified wood (Quartz/Chalcedony)

Mica Schist

Mica Schist (Schistose metamorphic rock rich in Muscovite/Biotite)

Quartzite

Quartzite (SiO2)

Fluorite

Calcium Fluoride (CaF2)

Green Aventurine

Silicon dioxide (SiO2) with fuchsite inclusions

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Milky Quartz (Druzy Geode fragment)

Silicon Dioxide (SiO2)

ABS Plastic (Acrylonitrile Butadiene Styrene)

(C8H8)x·(C4H6)y·(C3H3N)z

Yellow Calcite

Calcium Carbonate (CaCO3)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Petrified Wood

Silicified wood, primarily composed of Quartz (SiO2)

Lapis Lazuli

Lapis lazuli (a rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Sandstone (Red/Brown Variety)

Arenite (composed primarily of SiO2 with Fe2O3 iron oxide inclusions)

Orange Calcite

Calcium Carbonate (CaCO3)

Sandstone

Arenite (composed primarily of Quartz: SiO2)

Pyrite

Iron Sulfide (FeS2)

Iron Ore / Ironstone Concretion

Mixture of iron oxide/hydroxide minerals, likely some combination of Hematite (Fe2O3), Goethite (α-FeOOH), and Limonite (a general term for hydrated iron oxides of variable composition) or potentially Bauxite (a mixture of aluminum hydroxides, often with iron oxides, (Al(OH)3) and FeO(OH)). The visual characteristics strongly suggest iron-rich material.

Yellow Calcite

Calcium Carbonate (CaCO3)

Quartz on Matrix

Silicon Dioxide (SiO2)

Rhodonite

Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3

Puddingstone (Jasper Conglomerate)

Conglomerate (specific type: Jasper Conglomerate or Hertfordshire Puddingstone)

Olivine (Peridot when gem-quality)

Magnesium Iron Silicate, (Mg,Fe)2SiO4

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz (Microcrystalline/Chert)

Silicon Dioxide (SiO2)

Honey Calcite

Calcite (Calcium Carbonate, CaCO3)

Specularite (Specular Hematite)

Iron Oxide (Fe2O3)

Citrine Quartz

Silicon Dioxide (SiO2)

Quartz with Pyrite inclusions

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)

Pyrite

Iron Disulfide (FeS2)