Mineral (Impactite)

Talc Schist / Soapstone

Talc (Mg3Si4O10(OH)2)

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Limonite with Pyrite

Hydrated Iron Oxide Hydroxide, FeO(OH)·nH2O

Likely iron-rich granite or granitic gneiss

Quartz–feldspar rock with iron-oxide staining; exact identification is uncertain from the image

Fine-grained brown-gray rock, possibly andesite

Likely andesite or another fine-grained volcanic rock; exact identification is uncertain from the photo

Devil's Toenail (Fossil Oyster)

Gryphaea arcuata (Calcium Carbonate, CaCO3)

Quartz with Sulfide Inclusions

Silicon Dioxide (SiO2) with metallic mineral inclusions

Gneiss

Gneiss (a rock type, not a specific mineral with a formula)

Weathered geode or vug-bearing rock

Likely a quartz- or calcite-lined geode/vug in a host rock; exact minerals cannot be confirmed from the image

Limonite or Goethite (Ironstone)

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)

Kaolinite (China Clay)

Kaolinite (Al2Si2O5(OH)4)

Turquoise

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

Limonite

FeO(OH)•nH2O

Chrysocolla

Hydrated copper phyllosilicate, (Cu,Al)2H2Si2O5(OH)4·nH2O

Malachite

Copper carbonate hydroxide [Cu2CO3(OH)2]

Milky Quartz with Algae/Chlorite

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 based)

Limonite (Ironstone)

Limonite (FeOO·nH2O)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Sandstone (with Concretion)

Arenite / Quartzose Sandstone

Pyrite (on host rock)

Iron Sulfide (FeS2)

Yellow Calcite

Calcium Carbonate (CaCO3)

Limonite (Ironstone)

Goethite/Limonite (Hydrated iron(III) oxide-hydroxide)

Selenite (Satin Spar)

Gypsum (CaSO4·2H2O)

Turquoise (Dyed Howlite/Magnesite imitation)

CuAl6(PO4)4(OH)8·4H2O (Target mineral) / Ca2B5SiO9(OH)5 (Actual specimen: Howlite)

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Vesicular basalt

Basalt, commonly plagioclase feldspar + pyroxene ± olivine

Granite

Granite (felsic intrusive igneous rock)

Azurite Malachite (Mixed)

Azurite-Malachite; Azurite: Cu3(CO3)2(OH)2 / Malachite: Cu2CO3(OH)2

Likely serpentinite (green serpentine rock)

Serpentinite, composed chiefly of serpentine-group minerals (antigorite, lizardite, and/or chrysotile)

Quartz (Druzy)

Silicon Dioxide (SiO2)

Ruby (Raw Corundum)

Corundum (Al2O3) with Chromium traces

Limonite with Quartz

Hydrated Iron Oxide Hydroxide, FeO(OH)·nH₂O with SiO₂

Pegmatite

Pegmatite (felsic intrusive igneous rock)

Quartz in Greenstone

Metamorphic rock with quartz vein (SiO2 / mixed silicates)

Quartz crystal cluster in matrix

Silicon dioxide (SiO2)

Alabaster

Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)

Jasper Mushroom Carving

Silicon Dioxide (Microcrystalline Quartz, SiO2)

Copper Ore (Malachite and Limonite bearing)

Cuprite, Malachite, and Limonite mixture

Banded Iron Formation (Fragment)

Banded Iron Formation (BIF)

Calcite (Honey Calcite and Agate)

Calcium Carbonate (CaCO3)

Yellow Quartz

Silicon Dioxide (SiO2)