Unknown (Likely Sedimentary Or Metamorphic)

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Limonite pseudomorph after Pyrite

Goethite/Limonite FeO(OH)·nH2O

Banded gneiss cobble

Gneiss, commonly quartz–feldspar–mica gneiss

Banded dark pebble (likely gneiss or banded metamorphic rock)

Indeterminate from the image; possibly banded gneiss

Banded metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss, possibly migmatitic

Mica-rich schist (tentative)

Mica schist, likely muscovite–biotite schist; exact minerals cannot be confirmed from the image

Pyrite-bearing rock, possibly pyrite-rich schist or quartzite

Pyrite (iron disulfide, FeS₂) in a fine-grained metamorphic or quartz-rich matrix

Likely gneiss

Foliated quartz–feldspar gneiss; exact identification requires closer examination

Quartz-rich rock fragment

Milky quartz, primarily silicon dioxide (SiO₂), possibly quartzite or a feldspar-bearing vein rock

Rounded river pebble

Unidentified fine-grained clastic rock, possibly sandstone or mudstone

Metallic sulfide ore, likely pyrite-bearing rock

Pyrite (FeS₂), possibly with chalcopyrite and quartz/host rock

Quartz (Milky or Citrine-tinted)

Silicon Dioxide (SiO2)

Brown quartz-rich pebble (likely chert or weathered quartzite)

Quartz (SiO₂), possibly microcrystalline quartz/chert or quartzite

Mica-rich schist (probable)

Mica schist, composed mainly of mica minerals with quartz and possibly feldspar

Serpentine-rich ultramafic rock

Serpentinite (predominantly serpentine-group minerals: lizardite, chrysotile, and/or antigorite)

Green chalcedony (possibly chrysoprase) cabochon

Chalcedony, microcrystalline quartz (SiO₂); chrysoprase is nickel-colored chalcedony

Dark metamorphic rock, likely schist or phyllite

Quartz–mica schist/phyllite; chiefly quartz, mica, and feldspar

Likely pyrite-bearing rock fragment

Pyrite (FeS₂), possibly in a rock matrix

Pyritic Gneiss

Metamorphic Gneiss with Pyrite inclusions

Rounded stream pebbles (likely quartzite and iron-stained sandstone)

Quartzite (SiO₂), with a possible ferruginous sandstone pebble (quartz + iron oxides)

Milky quartz vein with iron-oxide staining

Quartz (SiO₂), likely vein quartz stained by hematite/goethite

Banded agate (rough or partly polished)

Agate, a microcrystalline variety of quartz (SiO₂; chalcedony)

Pegmatite

Granitic pegmatite, composed chiefly of quartz, feldspar, and mica

Likely weathered quartz-rich rock fragments

Uncertain; visually consistent with massive quartz or quartz-bearing sandstone

Pink-and-white banded quartzite or jasper

Quartzite, primarily microcrystalline SiO₂, possibly iron-stained quartz/chalcedony

Quartz-rich pegmatitic rock, probably granitic gneiss

Quartz–feldspar–mica gneiss; locally pegmatitic granite

Gneiss (Granitic Gneiss)

Gneiss

Weathered fossil bone fragment (possible mammal bone)

Fossilized vertebrate bone; exact taxon and age cannot be determined from the photo

Small blue-green mineral or stone bead

Unidentified opaque blue-green mineral; the image is insufficient for reliable species identification

Unidentified brown mineral/rock fragment

Indeterminate from image; possibly iron-stained quartz, feldspar, or weathered limonite

Quartz with iron staining

Silicon dioxide (SiO2)

Fine-grained metamorphic rock, likely slate or phyllite

Slate/phyllite; composition commonly quartz, mica, and chlorite

Dark foliated metamorphic rock, likely slate or phyllite

Fine-grained metamorphosed mudstone; exact identification is uncertain from the photograph

Fine-grained, foliated rock (possibly slate or phyllite)

Undetermined; likely slate or phyllite, composed mainly of quartz, mica, and chlorite

Quartz crystal (likely clear quartz)

Quartz, silicon dioxide (SiO₂)

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Quartz Vein in Matrix (Breccia / Host Rock with Quartz)

Silicon Dioxide (SiO2) in Host Rock Matrix

Unidentified weathered rock fragments

Likely mixed silicate rocks; specific identification requires testing

Quartz-rich rock, possibly milky quartz or quartzite fragment

Quartz (SiO₂), potentially quartzite if metamorphic

Fossilized marine shell fragment

Likely a bivalve or gastropod shell preserved as calcite (CaCO₃)

Tan quartz-rich rock, likely sandstone or weathered quartzite

Quartz sandstone; primarily SiO₂ with possible feldspar and iron-oxide cement

Quartz heart (likely milky/included quartz)

Quartz, silicon dioxide (SiO₂)