Mineral Like (Natural Glass)

Red Sandstone

Arenite (Iron-rich Sandstone)

Bornite

Cu5FeS4

Rainbow Hematite (Man-made/Treated)

Tumbled Hematite with Titanium/Anodized coating (Iron(III) oxide, Fe2O3)

Chert (and Jasper) Nodules in Limestone

Silicon Dioxide (SiO2) microcrystalline quartz

Sandstone

Clastic sedimentary rock (primarily quartz arenite)

Ironstone Concretion / Goethite Nodules

Ironstone (composed primarily of Goethite FeO(OH) and Limonite)

Diamond

Carbon (C), specifically in an isometric crystal system.

Red jasper (iron-rich chalcedony), possibly brecciated

Jasper: microcrystalline quartz, SiO₂, colored mainly by iron oxides/hydroxides

Fossiliferous Limestone

Fossiliferous Limestone (CaCO3)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Turquoise (Green variety)

Hydrous phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O

White Agate (Tumbled)

Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony

Shale

Lutaceous Sedimentary Rock

Yellow quartz, possibly citrine

Quartz (SiO₂), yellow variety likely citrine; may also be iron-stained quartz

Dyed Agate

Agate (Cryptocrystalline Quartz), SiO2

Citrine

Quartz (SiO₂)

Blue Goldstone

Man-made glass with crystalline copper/cobalt inclusions

Ruby

Corundum (Al2O3 with Chromium)

Druzy Quartz Geode (with Chalcedony)

Silicon Dioxide (SiO2)

Rough Diamond

Diamond (pure carbon, C)

Sandstone (Micaceous/Feldspathic variant)

Arenite (specifically subarkose or lithic arenite)

Vesicular Basalt (or Scoria)

Vesicular Basalt

Bismuth

Bismuth (Bi)

Sandstone (Quartzose)

Arenite (composed primarily of SiO2)

Diamond

Native Carbon (C)

Rough Diamond

Diamond (C)

Diamond (Faceted Colorless)

Diamond (Pure Carbon, C)

Tumbled chalcedony or quartz-rich stone

Microcrystalline quartz, SiO₂; possibly pale chert or chalcedony

Blue Quartzite (Blue Aventurine / Dumortierite Quartz)

Quartzite with inclusions (SiO2 with AlAl4BSi3O18)

Pink Tourmaline in Quartz

Elbaite [Na(Li,Al)3Al6(BO3)3Si6O18(OH)4] in Quartz [SiO2]

Obsidian

Volcanic glass (Mainly SiO2)

Rough Diamond

Native Carbon (C)

Emerald

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

Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)

Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)

Turquoise

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

Diorite

Intermediate Phaneritic Igneous Rock (Diorite)

Milk Quartz (Tumbled Pebble)

Quartz (Silicon Dioxide, SiO2)

Fluorite Octahedron

Fluorite (Calcium Fluoride, CaF2)

Turquoise

CuAl6(PO4)4(OH)8"""""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" • 4H2O (Hydrated copper and aluminum phosphate)

Shale

Fissile Mudstone

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)