Unknown

Iron-stained quartz-rich rock

Likely quartzite with iron-oxide staining; identification is provisional from the image

Polished bumblebee jasper

Calcite–orpiment/realgar-rich silicified volcanic rock (commercially called bumblebee jasper)

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

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

Likely serpentinite

Serpentinite, composed mainly of serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and minor chromite

Banded gneiss pebble

Foliated gneiss; likely quartz- and feldspar-rich, with dark mica or amphibole bands

Likely iron meteorite fragment

Unclassified Fe–Ni meteorite; possible stony-iron fragment

Water-worn pebble, likely quartz-rich sandstone or quartzite

Quartzite (tentative; a photograph cannot confirm whether the grains are fused or cemented)

Turquoise (rough, likely stabilized or treated)

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O

Porphyritic volcanic rock (likely andesite porphyry)

Porphyritic andesite; composition cannot be confirmed from the photograph

Tumbled amethyst with quartz and likely agate inclusions

Amethyst, purple quartz (SiO₂), with included/mixed quartz; crystalline variety of quartz

Pink-purple faceted gemstone ring (likely garnet)

Likely almandine–pyrope garnet, (Fe,Mg)₃Al₂(SiO₄)₃; identification from the image is uncertain.

Tumbled green stone, likely serpentine

Serpentine-group minerals, commonly antigorite or chrysotile; approximate composition Mg₃Si₂O₅(OH)₄

Tumbled serpentine (likely antigorite-rich)

Serpentine-group minerals, chiefly Mg₃Si₂O₅(OH)₄

Greenstone pebble, likely serpentine or epidote-bearing rock

Probable serpentinite (serpentine-group minerals: Mg₃Si₂O₅(OH)₄), possibly epidote-rich metamorphic rock

Polished granite (likely a granite countertop or floor slab)

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

Small brown mineral/rock fragment

Indeterminate; possibly weathered quartz-rich rock, ironstone, or a sulfide mineral

Serpentine-rich metamorphic rock

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

Weathered fossil fragment, possibly bone

Indeterminate fossilized bone; likely mineralized vertebrate bone (apatite-rich)

Chrysocolla-bearing copper ore (tentative)

Chrysocolla, a hydrated copper silicate; commonly intergrown with quartz and/or other copper minerals

Serpentinized ultramafic rock (likely serpentinite)

Serpentinite; chiefly antigorite/lizardite/chrysotile, commonly after peridotite (olivine–pyroxene)

Serpentinite (serpentinized ultramafic rock)

Serpentine-group minerals, chiefly lizardite and antigorite; commonly derived from peridotite

Likely native silver-bearing ore or metallic slag-like specimen

Uncertain from the photograph; possible native silver (Ag), but identification requires testing

Turquoise-colored ring stone (possibly turquoise or imitation)

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; identity cannot be confirmed from the image

Biotite granite (likely weathered granite)

Granite; quartz + feldspar + biotite, with accessory dark minerals

Tumbled serpentine

Serpentine-group minerals, chiefly antigorite, lizardite, or chrysotile; commonly Mg₃Si₂O₅(OH)₄

Rounded greenstone river cobble

Likely serpentinite or chlorite-rich metamorphic rock; exact identification requires testing

Tumbled serpentine or soapstone pebble

Serpentine-group minerals, chiefly antigorite/lizardite; possibly talc-rich steatite

Tumbled serpentine

Serpentinite; chiefly antigorite, lizardite, and/or chrysotile Mg₃Si₂O₅(OH)₄

Likely serpentinized ultramafic rock (serpentinite)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite, brucite, and pyroxene

Small metallic mineral fragment

Indeterminate; possibly galena, hematite, magnetite, or metallic meteorite fragment

Halite

Halite (Sodium Chloride, NaCl)

Serpentine-rich metamorphic cobble

Serpentinite, principally antigorite/lizardite Mg3Si2O5(OH)4, possibly with magnetite and minor carbonate

Possible bituminous coal

Coal, predominantly carbon with macerals and minor mineral impurities

Olivine-rich peridotite / olivine crystal fragment

Olivine, typically (Mg,Fe)₂SiO₄; possibly peridotite if the specimen is rock rather than a single crystal

Green copper-bearing rock, possibly chrysocolla-bearing matrix

Undetermined copper-mineralized rock; green areas may include chrysocolla, malachite, or chlorite

Green serpentine-rich rock (possibly serpentinite)

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

Serpentine-rich metamorphic rock

Serpentinite, dominated by serpentine-group minerals (antigorite/lizardite/chrysotile), with possible magnetite and carbonate

Green serpentine

Serpentine-group minerals, chiefly lizardite and antigorite; approximate formula Mg₃Si₂O₅(OH)₄

Serpentinite (probable)

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

Chalk or soft limestone fragment

Calcite-rich limestone; primarily calcium carbonate (CaCO₃)

Serpentinite pebble

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

Greenstone, possibly serpentine or altered basalt

Serpentinite (Mg₃Si₂O₅(OH)₄) or chlorite-epidote altered basalt; identification is uncertain from the image