Mineral (Extraterrestrial)

Quartz-rich pegmatite fragment

Granite/pegmatite; chiefly quartz (SiO₂) and feldspar, with possible biotite or tourmaline

Banded Sandstone (Water-worn Pebble)

Arenite with mineral banding

Limonite / Goethite Ironstone

FeO(OH)·nH2O (Hydrous iron oxide)

Fluorite Tower

Fluorite (Calcium Fluoride - CaF2)

Small metallic-looking rock fragment

Uncertain; possibly galena-bearing ore or mica-rich schist

Sandstone with Secondary Mineral Encrustation

Arenite with Silica/Calcite deposits (SiO2 or CaCO3)

Likely smoky quartz

Quartz (SiO₂), probably smoky variety

Sandstone with Ironstone Concretion

Arenite with Ferruginous Cement

Malachite

Malachite (Cu2CO3(OH)2)

Milky Quartz

Silicon Dioxide (SiO2)

Malachite

Copper Carbonate Hydroxide (Cu2CO3(OH)2)

Fossil bone, possibly a vertebra

Fossilized vertebrate bone; exact taxon cannot be determined from the image

Fossil Shark Tooth

Carcharocles (Otodus) sp. or similar fossilized Chondrichthyes tooth

Gneiss (rounded cobble)

Quartz–feldspar–mica gneiss; exact mineral proportions cannot be determined from the image

Gabbro (Water-Worn Pebble)

Gabbro (Plagioclase Feldspar and Pyroxene)

Magnetite

Magnetite (Fe3O4)

Granitic Gneiss

Gneiss (High-grade metamorphic rock)

Gneiss

Gneiss

Gneiss

Gneiss

Foliated amphibolite (likely augen or spotted amphibolite)

Amphibolite, composed chiefly of hornblende and plagioclase; exact identification requires close examination

Likely mica schist

Mica-rich schist, probably biotite–quartz–feldspar schist

Weathered conglomeratic rock, likely iron-stained sandstone

Probable ferruginous, clast-bearing sandstone; exact identification requires examination of a fresh surface

Copper-bearing altered rock, likely chrysocolla-bearing quartzite or breccia

Quartz (SiO₂) with copper silicate minerals, chiefly chrysocolla [approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O], and iron oxides

Granite

Intrusive Igneous Rock

Gneiss

Metamorphic Gneiss (High-grade regional metamorphism)

Quartz (Smoky/Brown variety)

Silicon dioxide (SiO2)

Raw greenish-blue quartz-bearing mineral specimen

Likely fluorite or chalcedony/quartz; exact identification requires hardness and crystal tests

Pyrite

Iron Disulfide (FeS2)

Gypsum (Selenite sand)

Calcium sulfate dihydrate (CaSO4·2H2O)

Fluorite on Host Rock

Calcium Fluoride (CaF2)

Pyrite

Iron Pyrite (FeS2)

Pyrite

Iron Sulfide (FeS2)

Eudialyte

Na15Ca6Fe3Zr3Si(Si25O73)(O,OH,H2O)3(Cl,OH)2

Quartz–calcite sulfide-bearing mineral specimen

Quartz (SiO₂) with likely calcite (CaCO₃) and iron sulfides, possibly pyrite (FeS₂); exact species requires testing

Amygdaloidal Basalt

Extrusive mafic igneous rock with amygdules

Blue-green glassy mineral specimen, likely aquamarine or pale fluorite

Tentatively beryl (Be₃Al₂Si₆O₁₈), aquamarine variety; identification is uncertain from the photograph

Likely pink granite

Granite, a coarse-grained felsic intrusive igneous rock, typically quartz + feldspar + mica

Polished rhyolite (likely rainforest jasper)

Rhyolite, a silica-rich volcanic rock; exact identification cannot be confirmed from the photo

Granite (likely weathered)

Granite, a quartz–feldspar–mica intrusive igneous rock

Tumbled pink granite

Granite (quartz, feldspar, and mica; exact variety uncertain)

Banded Sedimentary Rock

Stratified Siliciclastic / Arenite or Siltstone with Mineral Bands

Fossil Sea Urchin (Echinoid)

Echinoidea fossil (often replaced by silica or calcite)