Unknown (Likely Sedimentary Or Metamorphic)

Quartz-rich sandstone or quartzite fragment

Likely quartz arenite; possibly weakly metamorphosed quartzite (mostly SiO₂)

Rounded metamorphic cobble, likely gneiss or amphibolite

Banding-free biotite–quartz–feldspar gneiss or amphibolite; exact identification requires testing

Polished brecciated jasper (likely picture jasper)

Silica-rich microcrystalline quartz/chalcedony, SiO₂, with iron-oxide and clay inclusions

Tumbled orange chalcedony and a gray stone disk

Chalcedony (microcrystalline quartz, SiO₂); disk likely fine-grained sandstone or slate

Veined gneiss

Felsic to mafic banded gneiss, chiefly quartz–feldspar–biotite/hornblende

Weathered wood-like rock surface, likely slate or schist

Probable graphitic schist or slate; exact identification is uncertain from the image

Pyrite (likely), “fool’s gold”

Pyrite, FeS₂ (iron disulfide)

Quartz-rich mineral fragment

Quartz (silicon dioxide, SiO₂), possibly milky quartz

Foliated metamorphic rock, likely schist

Mica schist or chlorite schist; composition commonly quartz + mica/chlorite ± feldspar

Red jasper (likely brecciated or iron-stained jasper)

Jasper, microcrystalline quartz (SiO₂), colored chiefly by iron oxides

Foliated metamorphic rock, likely quartz-mica schist

Quartz–mica schist, commonly containing muscovite/biotite and quartz

Beach Pebble (Quartzite / Sandstone)

Quartz-rich sedimentary or metamorphic rock pebble

Mica-rich metamorphic rock, likely phyllite or mica schist

Muscovite- and/or biotite-bearing schist/phyllite; exact identification requires testing

Likely garnet-bearing metamorphic rock

Garnet amphibolite or garnet-bearing schist; chiefly almandine garnet (Fe₃Al₂Si₃O₁₂) with amphibole, mica, and quartz

Dark gray metamorphic cobble, likely basalt or hornfels

Probable hornfels or fine-grained basalt; exact identification requires testing

Mica Schist with Iron Staining

Muscovite/Biotite Schist

Tumbled limestone or marble

Calcite-rich carbonate rock; likely limestone (CaCO₃), possibly marble

Likely purple quartzite or purple chert

Quartzite/chert, predominantly microcrystalline SiO₂; exact identification requires testing

Banded Gneiss

Gneiss (Metamorphic Rock)

Weathered quartz-rich metamorphic rock (probable gneiss or quartzite)

Biotite–quartz–feldspar gneiss, possibly micaceous quartzite

Biotite-rich granite or granodiorite

Coarse-grained plutonic rock, likely granodiorite; composed mainly of quartz, plagioclase feldspar, potassium feldspar, and dark biotite/hornblende.

Likely foliated metamorphic rock (quartz-mica schist or gneiss)

Quartz–feldspar–mica metamorphic rock; exact identification requires a fresh surface and tests

Pink Garnet (likely Almandine or Rhodolite)

Garnet Group (Fe3Al2(SiO4)3 to Mg3Al2(SiO4)3)

Polished pyrite specimen

Pyrite (FeS₂), cubic iron disulfide

Weathered schist or gneiss

Quartz–feldspar–mica metamorphic rock

Granite Gneiss

Gneiss (High-grade metamorphic rock)

Quartz-rich metamorphic rock, likely quartzite

Quartzite, composed predominantly of quartz (SiO₂), with minor iron-oxide staining and possible feldspar/mica

Rounded quartz-rich pebble (likely vein quartz or quartzite)

Quartz, silicon dioxide (SiO₂); possibly quartzite if metamorphic

Jasper Conglomerate (Puddingstone)

Siliceous Conglomerate (Quartz and Jasper clasts in a fine-grained matrix)

Banded metamorphic pebble, likely gneiss

Foliated gneiss; quartz–feldspar–mica assemblage

Garnet-bearing gneiss

Biotite–garnet gneiss, typically quartz + feldspar + biotite + almandine garnet

Rounded white pebble, likely limestone or marble

Calcite-rich carbonate rock; possibly micritic limestone (CaCO₃) or marble

Weathered iron-stained quartzite or jasper

Quartzite dominated by quartz (SiO₂), with iron oxides/hydroxides such as hematite and limonite

Small metallic-gold mineral fragment, possibly pyrite

Pyrite (FeS₂), if confirmed

Carved red coral bead (likely coral or coral-colored resin)

Corallium spp. (precious coral; calcium carbonate, CaCO₃)

Foliated metamorphic rock, likely gneiss or schist

Quartz–feldspar–mica gneiss/schist; exact identification requires petrographic examination

Pale rounded quartz-rich pebble, likely quartzite

Quartzite (mostly microcrystalline SiO₂), possibly quartz-rich sandstone or vein quartz

Likely quartz fragment

Quartz (silicon dioxide, SiO₂), possibly milky quartz or quartz-rich rock

Banded Gneiss (with Quartz Vein)

Gneiss (SiO2 and varied Silicates)

Gneiss with Orthoclase Feldspar

Gneissic Metamorphic Rock with K-Feldspar inclusions

Gneiss (specifically Granitic Gneiss)

Gneiss

Banded metamorphic rock, likely gneiss or banded amphibolite

Undetermined foliated metamorphic rock; commonly quartz–feldspar–biotite gneiss or amphibolite