Mineraloid (Anthropogenic)

Likely metallic meteorite fragment

Undetermined iron or stony-iron meteorite; mineralogy requires testing

Small polished pebble, likely quartz or quartzite

Undetermined; possibly quartzite (quartz, SiO₂)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Reddish-brown crystalline rock, possibly weathered granite or garnet-bearing schist

Indeterminate; likely quartz–feldspar–mica rock with iron oxides, potentially garnet-bearing

Greenstone / River Jadeite pebble

Metavolcanic rock / Chlorite or Actinolite-rich schist

Green faceted gemstone, likely emerald

Beryl, Be₃Al₂Si₆O₁₈, colored green by chromium and/or vanadium

Ironstone pebble

Iron-oxide-cemented sediment, likely hematite- or goethite-rich

Serpentine-rich rock (likely antigorite serpentinite)

Serpentinite, composed mainly of serpentine-group minerals such as antigorite, lizardite, or chrysotile

Polished dark-blue cabochon, possibly blue sodalite

Undetermined; blue sodalite is a possible identification (Na₈Al₆Si₆O₂₄Cl₂)

Small rounded yellow pebble, likely quartz-rich rock

Indeterminate from image; possibly iron-stained quartz or chert

Small metallic meteorite-like specimen

Unclassified iron-rich meteorite candidate; possibly an ordinary chondrite or terrestrial slag

Granite Pegmatite

Granitic Pegmatite (composition: SiO2 with KAlSi3O8)

Tumbled purple rock, likely lepidolite-bearing mica schist

Lepidolite-rich mica schist; lepidolite K(Li,Al)₃(Si,Al)₄O₁₀(F,OH)₂, possibly mixed with quartz and feldspar

Mixed Mineral and Crystal Assortment

Various silicate and oxide minerals

Onyx Marble

Calcite (CaCO3) or Aragonite

Porphyritic Rhyolite

Felsic Extrusive Igneous Rock

Mixed mineral and shell specimen assortment

Primarily unidentified quartz-/feldspar-like pebbles with possible dark basalt or iron-rich fragments; white pieces may include shell or calcite

Fossil brachiopod shell

Brachiopoda; exact genus and species cannot be determined from the image

Dark volcanic rock, likely basalt

Basalt (fine-grained mafic igneous rock; commonly plagioclase, clinopyroxene, and olivine)

Rounded basalt pebble

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase feldspar and pyroxene, with possible olivine

Weathered green metamorphic rock, possibly serpentinite or greenstone

Likely serpentinite (serpentine-group minerals) or chlorite/epidote-rich greenschist; exact identification requires testing

Dark gray fine-grained stone, likely basalt

Basalt; primarily plagioclase feldspar and pyroxene, commonly with minor olivine and iron oxides

Weathered metal-rich igneous rock, likely basalt or komatiitic peridotite

Probable altered mafic–ultramafic rock containing pyroxene/amphibole, olivine, iron oxides, and possible metallic sulfides

Mica-rich pegmatitic granite

Granitic pegmatite, chiefly quartz, feldspar, and muscovite/biotite mica

Eclogite

Eclogite (Omphacite-Garnet rock)

Serpentine-bearing metamorphic rock (likely chromite/vesuvianite-bearing serpentinite)

Serpentinite, chiefly serpentine-group minerals [(Mg,Fe)₃Si₂O₅(OH)₄], with dark accessory minerals

Serpentinized ultramafic rock with magnesite

Serpentinite, chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with likely magnesite (MgCO₃) and minor chromite/magnetite

Quartzite

Quartzite (primarily SiO2)

Granite

Phaneritic Felsic Igneous Rock

Granite

Phaneritic Felsic Igneous Rock

Granite

Phaneritic Felsic Igneous Rock

Scoria (vesicular volcanic rock)

Basaltic to andesitic scoria; chiefly plagioclase, pyroxene, and volcanic glass

Drill Core Sample

Cylindrical Rock Core (Specific mineralogy varies by extraction site)

Tumbled brown jasper

Microcrystalline quartz (SiO₂), commonly called jasper when opaque and impurity-colored

Amazonite-bearing feldspar (likely raw amazonite)

Amazonite, a blue-green variety of microcline feldspar; KAlSi₃O₈

Green fluorite crystal

Fluorite (calcium fluoride, CaF₂)

Quartz Pebble

Silicon Dioxide (SiO2)

Yellow chalcedony (likely dyed or heat-treated)

Microcrystalline quartz, SiO₂ (chalcedony)

Likely black tourmaline (schorl)

Schorl, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Polished sodalite-bearing rock

Likely sodalite in a feldspar-rich host; exact rock identification is uncertain from the image

Likely serpentine-rich pebble

Serpentinite, composed mainly of serpentine-group minerals (e.g., antigorite, lizardite, or chrysotile)

Banded gneiss cobble

Gneiss, typically quartz–feldspar–mica assemblage