Mineral (Processed Metal)

Polished serpentine pendulum

Serpentine-group minerals, chiefly antigorite/lizardite; approximate formula Mg₃Si₂O₅(OH)₄

Jasper and Chalcedony Composite

Silicon Dioxide (SiO2) microcrystalline quartz

Milky Quartz

Silicon Dioxide (SiO2)

Granite

Granite (a plutonic igneous rock composed primarily of quartz, feldspar, and mica)

Snowflake Obsidian

Volcanic Glass with Cristobalite Inclusions

US Penny

Cuprum (Copper: Cu) and Zincum (Zinc: Zn) Alloy

Pyrite

Iron Pyrite (FeS2)

Yellow Calcite

Calcium Carbonate (CaCO3)

Carved Stone Turtle

Carved Soapstone and Quartz

Mixed Mineral Collection (Quartz, Amethyst, Rose Quartz, Pyrite, etc.)

Mixed Silicates and Sulfides (SiO2, FeS2)

Quartz (with probable host rock)

Silicon Dioxide (SiO2)

Mica schist, likely biotite–muscovite schist

Mica schist; predominantly quartz, feldspar, biotite and/or muscovite mica. Exact mineral composition cannot be confirmed from the photograph alone.

Botryoidal Pyrite

Iron Sulfide (FeS2)

Limonite Concretion

FeO(OH)·nH2O (Hydrated Iron Oxide)

Limonite (Iron Ore)

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

Agate (specifically, multi-colored or pastel-dyed agate)

Silicon dioxide (SiO2) - specifically, a cryptocrystalline variety of quartz known as Chalcedony, with banding classified as Agate. (If it were Fluorite, the chemical formula would be Calcium Fluoride - CaF2).

Orange Calcite

Calcium Carbonate (CaCO3)

Opalite (Man-made Glass)

Synthetic Silicon Dioxide Glass (SiO2 + metal oxides)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Shark Tooth Fossil

Carcharocles megalodon or similar extinct shark tooth

Black Sapphire

Corundum (Al2O3)

Snowflake Obsidian

Volcanic Glass with Cristobalite inclusions

Man-made Glass (Tumbled/Shaped)

Amorphous Silicon Dioxide (SiO2) with metal oxide colorants

Moqui Marble

Hematite-Goethite Concretion (Fe2O3 / FeO(OH))

Spinifex Texture Komatiite

Komatiite (Ultramafic Volcanic Rock)

Quartz Pebble

Silicon Dioxide (SiO2)

Banded Gneiss

Gneiss (SiO2 enriched metamorphic rock)

Diamond

Native Carbon (C)

Kidney Stone

Calcium Oxalate (CaC2O4·nH2O)

Quartzite

Quartzite (SiO2)

Quartzite

Quartzite (SiO2)

Quartzite River Cobble

Quartzite (primarily SiO2)

Limonite Geode (Ironstone Concretion)

Limonite [FeO(OH)·nH2O] with possible Quartz or Calcite interior

Apophyllite cluster

Fluorapophyllite-(K), KCa4(Si8O20)(F,OH)·8H2O

Fossilized Tooth Fragment

Vertebrate Fossil (Mammalia indet.)

Lepidolite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Kidney Stone

Nephrolith (typically Calcium Oxalate - CaC2O4)

Diamond

Native Carbon (C)

Fossil Shark Tooth

Selachii fossil

Diamond (Cut Gemstone)

Natural Carbon (C)

Larimar

Pectolite (NaCa2Si3O8(OH))

Kidney Stone

Nephrolithiasis (Calcium Oxalate, Hydroxyapatite, or Uric Acid)