Anthropogenic (Man Made Product Subject To Geological Processes)

Unidentified polished stone fragments

Indeterminate; likely mixed lapidary specimens, possibly jasper, agate, or quartz-bearing rock

Sandstone (Red/Brown Variety)

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

Gold Nugget

Native Gold (Au)

Quartz pebble

Silicon dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Quartzite

Metamorphic Quartzite (SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Basalt

Extrusive Igneous Rock

Olivine in Basalt (Peridotite Xenolith)

Forsterite-rich Olivine (Mg2SiO4) in Aphanitic Basalt

Coquina

Bioclastic Limestone

Quartz with Pyrite inclusions

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)

Zirconia (Ceramic) & Ion-X Glass

Zirconium Dioxide (ZrO2) and Ion-strengthened Aluminosilicate Glass

Massive Quartz

Silicon dioxide (SiO2)

Limestone with Calcite Crystals

Sedimentary Rock containing Calcium Carbonate (CaCO3)

Quartz (Microcrystalline/Chert)

Silicon Dioxide (SiO2)

Mixed rounded rock and mineral gravel

Predominantly weathered basalt, quartz-rich fragments, and iron-stained silicate rocks; exact species cannot be determined reliably from the image

Quartz (Milky or Druzy variety)

Silicon Dioxide (SiO2)

White Quartz Pebble

Silicon Dioxide (SiO2)

Rhodonite

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

Diamond

Carbon (C)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Pyrite

Iron Sulfide (FeS2)

Chert (variations include Flint/Novaculite)

Chert (formula: SiO2)

Shale and Pebble Fragment

Sedimentary Rock (Mudstone/Shale with Silica Pebble)

Limestone (or Calcite Pebble)

Calcium Carbonate (CaCO3)

Diamond (in jewelry setting)

Adamantine Carbon (C)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Diamond (or Simulant)

Carbon (C) or relevant simulant formula (e.g., ZrO2 for Cubic Zirconia)

Ferromanganese Nodule

Polymetallic Nodule (composed primarily of MnO2 and Fe2O3)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Slag

Clear Quartz Cluster

Quartz (Silicon Dioxide, SiO2)

Quartz (Variety: Citrine or Tumbled Chalcedony)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

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.

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Coal (Anthracite or Bituminous)

Lithified plant matter (Carbon)

Quartzite

Metamorphic Quartz Sandstone

Pyrite

Iron Sulfide (FeS2)

Quartz

Quartz (SiO₂)

White Quartz Pebble

Silicon Dioxide (SiO2)

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)