Unknown (Likely Sedimentary Or Metamorphic)

Small red-brown mineral or rock fragment

Unidentified; possibly iron-oxide-rich jasper, garnet, or weathered sulfide

Serpentine-rich rock

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄

Green serpentine or nephrite-like stone

Serpentinite, chiefly serpentine-group minerals; exact identification would require testing

Rounded gray stone, likely slate or fine-grained sandstone

Probable slate (low-grade metamorphosed shale) or lithic sandstone; exact identification requires testing

Serpentinite (probable)

Serpentinite; chiefly serpentine-group minerals (antigorite/lizardite/chrysotile), commonly with magnetite and minor olivine/pyroxene

Weathered volcanic rock, likely andesite

Porphyritic andesite (tentative; image alone cannot confirm composition)

Serpentinite pebble

Serpentinite; chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), commonly with magnetite, chromite, and carbonate

Brecciated jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), with iron-oxide staining

Bituminous coal

Coal, predominantly carbon with macerals and minor clay/pyrite minerals

Likely slate fragments

Slate, a fine-grained metamorphic rock composed chiefly of quartz, mica, and chlorite

Likely mica-rich metamorphic rock (schist)

Mica schist, probably containing muscovite and/or biotite with quartz and feldspar

Small white mineral fragment

Likely quartz (SiO₂), possibly calcite (CaCO₃)

Iron-stained quartz fragment (probable quartzite or chert)

Quartz, SiO₂; possibly iron-oxide-stained microcrystalline silica

Dark gray rounded river pebble

Likely basalt or fine-grained volcanic rock; exact identification requires testing

Possible basalt or other dark volcanic rock

Undetermined fine-grained mafic volcanic rock; basalt is a possibility

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Carnelian

SiO2 (Silicon Dioxide with Iron Oxide impurities)

Yellow Aventurine

Silicon Dioxide with inclusions (SiO2 + Muscovite/Fuchsite)

Mixed collection of common river stones

Varied lithologies, visibly including quartz-rich rock, dark mafic rock, sandstone, and purple quartz-bearing material

Likely pyrite-bearing rock

Pyrite (FeS₂), possibly disseminated in a host rock

Pyrite-bearing rock (likely pyrite-rich ore)

Pyrite, FeS₂, in a fine-grained host rock

Chalcedony (Agate) Pebble

Silicon Dioxide (SiO2)

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Clear quartz crystals

Quartz (silicon dioxide, SiO₂)

Unknown small pale rock fragment

Unidentified light-colored granular mineral aggregate; likely quartz-rich material or limestone

Quartz-rich limestone or calcitic marble

Calcite (CaCO₃), possibly with quartz (SiO₂)

Fossilized bone fragment (probable mammalian tooth or bone)

Mineralized bone, commonly hydroxyapatite [Ca5(PO4)3(OH)] replaced or impregnated by silica/calcite

Banded gneiss (likely garnet-biotite or quartz-feldspar gneiss)

Gneiss; predominantly quartz (SiO₂), feldspar, and dark biotite/amphibole

Banded gneiss pebble

Gneiss, likely quartz–feldspar–biotite gneiss

Small rough mineral or rock fragment (not identifiable from the image)

Undetermined; the specimen is too small and lacks diagnostic visible features for a reliable identification

Gold ring with a dark, possibly gemstone setting

Gold alloy; the dark setting is not identifiable from the image

Halite (Rock Salt)

Halite (NaCl)

Possible iron-rich meteorite fragment

Unidentified Fe–Ni meteoritic material; identification cannot be confirmed from this blurry image

Quartz pebble

Silicon dioxide (SiO2)

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Orange Calcite (likely polished specimen)

Calcite

Likely banded gneiss

Gneiss (quartz–feldspar–mica-rich rock; exact identification uncertain from the photo)

Rounded quartz-rich cobble

Likely quartzite or quartz-rich sandstone; exact identification requires a fresh break or hardness test

Polished serpentine pendant

Serpentinite, chiefly serpentine-group minerals (lizardite, antigorite, chrysotile), commonly with magnetite and carbonate

Banded gneiss pebble

Gneiss, likely quartz–feldspar–mica gneiss

Small dark pebble, possibly basalt

Unidentified fine-grained mafic rock; basalt is a tentative visual match

Small fossilized tooth, possibly a shark tooth

Indeterminate fossil tooth; species cannot be identified from this image