Mineral (Impactite)

Gneiss

Gneiss

Banded gneiss pebble

Gneiss, composed chiefly of quartz, feldspar, and mica/amphibole

Gneiss

Gneiss (High-grade Metamorphic Rock)

Gneiss

Gneiss (High-grade metamorphic rock)

Gneiss

Gneiss

Granite Pebble (Weathered)

Phaneritic Felsic Igneous Rock

Banded Gneiss

Gneiss (Metamorphic Rock)

Diorite

Diorite

Limonite (often after Pyrite)

Limonite (FeO(OH)·nH2O)

Copper Ore (with Malachite/Chrysocolla and Iron Oxides)

Secondary Copper Minerals (Cu2(CO3)(OH)2 / (Cu,Al)2H2Si2O5(OH)4·nH2O)

Lepidolite

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

Vanadinite

Pb5(VO4)3Cl

Turquoise

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

Turquoise

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

Limonite

FeO(OH)•nH2O

Hematite (Botryoidal / Kidney Ore)

Iron Oxide (Fe2O3)

Limonite with Ironstone

Limonite (hydrated iron(III) oxide-hydroxides), FeO(OH)·nH2O

Fluorite

Calcium fluoride (CaF2)

Turquoise (with Hematite)

CuAl6(PO4)4(OH)8·4H2O

Limonite (Iron Ore)

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

Limonite (Ironstone)

Hydrous ferric oxides (FeO(OH)·nH2O)

K2 stone (azurite–granite)

Biotite granite hosting blue azurite (Cu₃(CO₃)₂(OH)₂), often with malachite and quartz

Limonite (Yellow Ochre)

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

Tumbled greenstone pebble

Greenstone (metamorphosed mafic volcanic rock; commonly chlorite, actinolite, epidote, and albite)

Ironstone Concretion (Limonite/Goethite)

Ferruginous Sandstone or Limonite (FeO(OH)·nH2O)

Sandstone with Iron Concretion

Arenite with Limonite/Goethite Concretion

Limonite on Sandstone

Iron Oxyhydroxide (FeO(OH)·nH2O) on Quartz Sandstone

Dark mafic rock, likely basalt

Basalt; chiefly plagioclase feldspar and pyroxene, commonly with minor olivine and magnetite

Probable fossil-bearing rock or mineral concretion

Unidentified carbonate-rich concretion with a possible fossil inclusion

Small rounded light-colored mineral pebble

Indeterminate; possibly quartz, feldspar, or calcite

Small greenish crystal/mineral fragment

Indeterminate; possibly olivine, quartz, or a green gemstone fragment

Mixed rock and mineral specimens

Predominantly quartz-rich rocks, with a possible malachite-bearing specimen; exact identification is uncertain from the image

Hematite

Iron Oxide (Fe2O3)

Granite cobble

Granite, a coarse-grained felsic intrusive igneous rock, chiefly quartz, potassium feldspar, plagioclase, and dark biotite or hornblende

Likely gneiss

Quartz–feldspar–mica gneiss

Fossilized Shark Tooth (Megalodon or Carcharocles species fragment)

Otodus megalodon / Carcharocles spp. (Apatite / Calcium Phosphate)

Fossilized Shark Tooth

Chondrichthyes (class)

Fluorite

Calcium Fluoride (CaF2)

Mixed Gemstone and Mineral Collection

Mixed Silica and Carbonate minerals (SiO2, CaSO4·2H2O, etc.)

Malachite

Copper Carbonate Hydroxide, Cu2CO3(OH)2

Magnetite Sand (Black Sand)

Magnetite (Fe3O4)

Vesicular basalt (likely weathered lava rock)

Basalt; chiefly plagioclase, pyroxene, and often olivine