All rocks & minerals

Fossil-bearing limestone

Bioclastic limestone, composed mainly of calcite (CaCO₃), with embedded shell fossils

Ironstone concretion (likely limonite/goethite-rich)

Hydrated iron oxides, chiefly goethite (α-FeO(OH)) and/or limonite; exact identification requires testing

Scoria (vesicular volcanic rock)

Scoria, typically basaltic or andesitic volcanic rock; commonly composed of plagioclase, pyroxene, and iron oxides

Dark limestone or mudstone pebble with calcite veins

Fine-grained carbonate rock, likely limestone (dominantly calcite, CaCO₃); exact identification requires testing

Polished fossiliferous stone, possibly fossiliferous limestone

Fossil-bearing carbonate rock; exact fossil and host-rock identification cannot be confirmed from the image

Polished greenstone pebble

Greenstone (chlorite–epidote–actinolite-rich metamorphosed mafic rock)

Green-gray banded agate (likely polished chalcedony)

Chalcedony, microcrystalline quartz (SiO₂); banding may be quartz-filled fractures

Fossiliferous limestone pebble

Calcite-rich bioclastic limestone (primarily CaCO₃)

Chalcedony (Agate / Quartz Pebble)

Microcrystalline Silicon Dioxide (SiO2)

Chert (flint), likely a weathered nodule fragment

Microcrystalline quartz (SiO₂), commonly termed chert or flint

Vesicular basalt (lava rock)

Vesicular basalt, a basaltic volcanic rock composed mainly of plagioclase, pyroxene, and commonly olivine

Quartz geode (druzy quartz)

Quartz, SiO₂, lining a cavity in a pale host rock

Druzy quartz on a yellow-brown host, likely agate or chalcedony

Quartz, SiO₂; microscopic drusy quartz crystals coating chalcedony

Likely quartz-rich rock (milky quartz or quartzite)

Quartz-rich metamorphic rock, likely quartzite; predominantly silicon dioxide (SiO₂)

Galena (lead sulfide)

Galena, PbS

Milky quartz

Quartz (SiO₂), likely massive milky quartz

Milky quartz

Quartz (silicon dioxide, SiO₂)

Mottled purple-and-cream rough mineral specimen, likely lepidolite-bearing pegmatite

Probably lepidolite (lithium mica; K(Li,Al)₃(Si,Al)₄O₁₀(F,OH)₂) with light-colored quartz or feldspar; identification uncertain from image

Purple fluorite (rough crystal fragment)

Fluorite, CaF₂

Raw amethyst (purple quartz)

Quartz, SiO₂; purple color typically comes from iron-related defects and natural irradiation

Galena (likely)

Galena, lead sulfide (PbS)

Green serpentine pebble (possibly serpentine-rich rock)

Serpentinite, composed chiefly of serpentine-group minerals such as antigorite, lizardite, or chrysotile; exact identification requires testing

Gray chalcedony (rough, possibly agate-grade)

Chalcedony, microcrystalline quartz (SiO₂)

Polished jasper

Jasper, an opaque, microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides

Kaolinite (clay mineral)

Kaolinite, Al₂Si₂O₅(OH)₄

Clear quartz (rock crystal)

Quartz — silicon dioxide (SiO₂)

Conglomerate (likely pebble-rich rock)

Lithified conglomerate; exact composition cannot be determined from the photo

Mica-rich schist

Mica schist, likely muscovite–biotite schist with quartz and feldspar

Iron-rich conglomerate or breccia (tentative)

Poorly sorted lithic conglomerate/breccia, with iron-oxide staining; exact composition cannot be determined from the photo

Weathered volcanic breccia (possible basaltic-andesite breccia)

Volcanic breccia: angular to subrounded volcanic clasts in a finer volcanic matrix; exact composition cannot be confirmed from the photograph

Granite

Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz, feldspar, and mica

Polished agate (likely carnelian or orange chalcedony)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide coloring

Weathered granitoid (likely granite or granodiorite)

Quartz–feldspar plutonic rock; exact type cannot be confirmed from the photograph

Tumbled stones, likely jasper or agate

Likely microcrystalline quartz (SiO₂), varieties such as jasper or agate; exact identification is not possible from the image

Milky quartz with iron staining and dark mineral inclusions

Quartz (SiO₂), with iron-oxide staining and likely dark mica or other inclusions

Pegmatitic granite

Quartz–feldspar–mica granite pegmatite

Polished porphyritic granite

Porphyritic granitoid, composed mainly of quartz, feldspar, and mica

Quartzite

Quartz-rich quartzite, composed predominantly of recrystallized quartz (SiO₂)

Tumbled fossil wood (petrified wood)

Silicified wood; commonly quartz or chalcedony (SiO₂) replacing the original wood

Milky quartz (quartz-rich rock)

Quartz, SiO₂; the specimen appears to be massive milky quartz, possibly with minor feldspar or mica

Iron-rich lateritic rock (ironstone)

Goethite–hematite-rich ferruginous material; exact identification requires testing

Quartz-rich granitic rock

Likely granite or granitic pegmatite, composed mainly of quartz and feldspar with minor dark mica; exact identification requires closer examination.