Man Made Material (Metal)

Polymictic breccia, possibly volcanic breccia

Polymictic clastic breccia; likely a matrix-supported breccia containing lithic fragments, quartz, feldspar, and dark mafic minerals

Carnelian/chalcedony rough

Microcrystalline quartz (SiO₂), iron-oxide-colored chalcedony

Basaltic Tuff / Volcanic Breccia

Pyroclastic Breccia / Lithic Tuff

Chert (and Jasper/Flint variety)

Cryptocrystalline Quartz (SiO2)

Blue Quartz (Aventurine)

Silicon Dioxide (SiO2) with fibrous inclusions (commonly Dumortierite)

Tiger’s-eye bead bracelet

Chatoyant quartz, principally quartz (SiO₂) with pseudomorphic fibrous crocidolite/goethite inclusions

Banded iron formation fragment (likely hematite–magnetite ironstone)

Banded iron formation; chiefly hematite (Fe₂O₃), magnetite (Fe₃O₄), and microcrystalline quartz (SiO₂)

Greisen

Greisen

Tektite (Indochinite)

Tektite (High-silica impact glass)

Chert Pebble

Microcrystalline silica (SiO2)

Sandstone

Arenite (SiO2 primarily)

Limestone

Calcium Carbonate (CaCO3)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Orbicular Granite (specifically Mustard or Yellow Tonalite/Granodiorite)

Orbicular Quartz Diorite / Tonalite

Limestone (Weathered)

Sedimentary Carbonate Rock (CaCO3)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Diamond

Carbon (C)

Tumbled or rough turquoise-like specimen

Turquoise, hydrated copper aluminum phosphate — CuAl₆(PO₄)₄(OH)₈·4H₂O; identification is uncertain from the image

Polished black stone egg, probably black obsidian

Obsidian, a natural volcanic glass; composition primarily silica-rich glass (approximately SiO₂), with variable iron and other trace elements

Emerald

Beryl (Be₃Al₂Si₆O₁₈), specifically the green variety colored by trace amounts of chromium or vanadium.

Chert / Flint

Cryptocrystalline quartz (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Granite

Granite

Limestone

Calcium Carbonate (CaCO3)

Garnet Schist

Garnetiferous Mica Schist

Sandstone

Arenite (primarily SiO2)

Coquina or Fossiliferous Limestone

Fossiliferous Calcarenite (CaCO3)

Lapis Lazuli

A metamorphic rock primarily composed of lazurite (Na,Ca)8[(S,SO4,Cl)2|(Al6Si6O24)], calcite (CaCO3), and pyrite (FeS2).

Weathered porphyritic basalt

Basalt, likely plagioclase-phyric basalt; primarily a fine-grained aggregate of plagioclase feldspar, clinopyroxene, and possibly olivine or iron-titanium oxides

White Marble

Metamorphic Limestone (CaCO3)

Pyrite

Iron Disulfide (FeS2)

Fossil bivalve shell

Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features

Sandstone

Arenite (primarily SiO2 with Fe2O3)

Diamond

Carbon (C)

N/A - Image does not contain a rock or mineral

Anthropogenic textile material

Banded Calcite (often sold as Mexican Onyx or Aragonite)

Calcite/Aragonite (Calcium Carbonate, CaCO3)

Engineer Quartz/Quartzite

SiO2 (Silicon Dioxide with binders)

Cubic Zirconia

Zirconium dioxide (ZrO2)

Amethyst

SiO2 (Silicon Dioxide)

White Marble

Recrystallized Calcite (CaCO3)

Pearl (Biogenic Mineraloid)

Calcium carbonate (Aragonite) and Conchiolin, CaCO3