Industrial Byproduct (Anthropogenic Material)

Amethyst crystal

Quartz, SiO₂; purple variety colored mainly by iron impurities and irradiation

Vesuvianite (Idocrase)

Vesuvianite, Ca10(Mg,Fe)2Al4(SiO4)5(Si2O7)2(OH)4

Fossil coral, likely solitary rugose coral

Rugosa (possibly colonial tabulate coral); calcite/aragonite replaced by calcite

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂), cryptocrystalline to microcrystalline variety

Polished ocean jasper

Jasper, microcrystalline quartz (SiO₂), commonly with iron oxides and chlorite/minor accessory minerals

Quartz River Pebble

Silicon Dioxide (SiO2)

Quartzite

Metamorphic Quartzite (predominantly SiO2)

Likely anthracite coal

Anthracite; predominantly carbon (C), with minor mineral impurities

Rough Sapphire (Corundum)

Corundum (Al2O3)

Sandstone (with Iron Staining)

Sandstone (mainly Quartz, SiO2, with Iron Oxides like Goethite/Hematite)

Polished orbicular jasper

Orbicular jasper; microcrystalline quartz (SiO₂) with hematite/goethite and other silicate inclusions

Polished blue stone, likely sodalite or dyed agate

Sodalite: Na₈(Al₆Si₆O₂₄)Cl₂; exact identification requires testing

Tumbled rose quartz

Quartz (SiO₂), pink variety

Quartzite with Sandstone/Iron staining

Metamorphic Quartzite (SiO2)

Honey Calcite

Calcium Carbonate (CaCO3)

Peridot (Olivine)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Milky Quartz with Dendritic Inclusions

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Sandstone

Arenite (primarily SiO2)

Diamond (set in a gold ring)

Carbon (C) - Adamantine cubic carbon

Likely ironstone concretion or weathered iron-rich rock

Goethite/hematite-bearing limonite (FeO(OH)·nH₂O / Fe₂O₃)

Chert (variations include Flint/Jasper)

Chert (SiO2)

Quartzite

Quartzite (predominantly SiO2)

Likely rough metallic meteorite fragment

Unclassified iron or stony-iron meteorite; identification is uncertain from the image alone

Iron-stained Quartz Vein

Silicon Dioxide (SiO2) with Limonite/Hematite inclusions

Water and Silt (Sedimentary Environment)

Suspended Sediment / H2O (dihydrogen monoxide)

Weathered iron-rich stone, possibly jasper or chert

Microcrystalline quartz (SiO₂), likely stained by iron oxides/hydroxides

Likely polished bronzite or serpentine-rich rock

Probable bronzite, an iron-bearing orthopyroxene (Mg,Fe)SiO₃; exact identification requires testing

Fossilized bivalve shell fragment

Pectinid or related scallop bivalve; shell originally composed mainly of calcite (CaCO₃)

Polished black tourmaline (likely schorl)

Schorl, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Diamond

Carbon (C)

Sandstone

Arenite (SiO2 principal)

Ruby (Raw Corundum)

Corundum (Al2O3 with Chromium impurities)

Weathered rounded stone, likely quartz-rich sandstone or granitoid

Indeterminate feldspathic quartz rock; possibly weathered granite or granitic gneiss

Polished ocean jasper (orbicular jasper), probable

Microcrystalline quartz (SiO₂) with iron-oxide and other mineral inclusions

Unidentified brown mineral/rock fragment

Indeterminate from image; possibly iron-stained quartz, feldspar, or weathered limonite

Cubic Zirconia (CZ)

Cubic Zirconium Dioxide (ZrO2)

Serpentine

Antigorite/Chrysotile/Lizardite (Mg,Fe)3Si2O5(OH)4

Chert (Flint)

Chert (SiO2)

Greywacke

Lithic Sandstone (Greywacke)

Raw amethyst quartz crystal

Quartz, silicon dioxide (SiO₂), purple variety amethyst

Polished Picasso jasper

Silicified carbonate rock, commonly marketed as Picasso jasper; composition varies and is not a single mineral species