Not A Geological Specimen

Possible basalt or iron-rich slag-like geological specimen

Basalt (tentative); predominantly plagioclase and pyroxene, possibly with magnetite/iron oxides

Stamped concrete made to resemble flagstone

Portland-cement concrete with decorative stone-textured finish

Quartz Vein in Greenstone

SiO2 hosted in metamorphosed basalt

Pearl stud earrings

Pearl, primarily aragonite (CaCO₃) and conchiolin

Uncertain dark-and-white rock fragment

Likely a mixed lithic specimen, possibly quartz-bearing granite or ore; exact identification is not possible from the photograph

Sandstone

Quartz Arenite / Clastic Sedimentary Rock

Flint

SiO2 (Microcrystalline quartz / Chert)

Likely jade and pink gemstone jewelry

Green material may be jadeite (NaAlSi₂O₆) or nephrite (Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂); pink beads are unidentified, possibly quartz or coral

Glass / Silicon Dioxide (Man-made)

SiO2 (Amorphous Silicon Dioxide)

Quartzite Pebble

Metamorphic Quartzite (predominantly SiO2)

Mixed collection of tumbled minerals and rough specimens

Multiple species visible; likely fluorite, quartz/chalcedony, pyrite, tiger’s eye, rose quartz, and possibly labradorite or agate

Basalt

Mafic extrusive igneous rock

Polished ocean jasper (orbicular jasper), probable

Silicified orbicular rhyolite; chiefly microcrystalline quartz (SiO₂)

Clay Concretion / Mudstone Nodule

Sedimentary Concretion (Argillaceous)

Chert (Flint)

Microcrystalline quartz (SiO2)

Possible sea glass (naturally frosted glass), not a confirmed geological specimen

Man-made silicate glass; composition varies, commonly soda-lime glass

Lapidary Wax (imitation/wax model)

Hydrocarbon wax blend with colorant (imitating Lapis Lazuli/Emerald)

Sandstone concretion

Sedimentary concretion

Banded Sedimentary Rock

Siliciclastic sedimentary rock

N/A - Man-made object (Jewelry Chain)

Antiqued or Oxidized Metal Chain (often Steel or Brass)

Blue Slag Glass

Amorphous Silica (Industrial byproduct)

Pyrite-bearing Schist

Metamorphic rock with FeS2

Pearl

Biogenic calcium carbonate; mainly aragonite (CaCO₃), sometimes calcite, in nacre

Polished orbicular/porphyritic granite or breccia

Likely potassium-feldspar–quartz granite with amphibole/biotite and epidote; exact variety uncertain from the image

Tumbled orbicular/patterned jasper (likely brecciated jasper)

Microcrystalline quartz (SiO₂) with iron-oxide and possibly calcite/chalcedony veining

Sandstone Concretion

Sedimentary Concretion (Quartz sand bound by mineral cement)

River Cobble (Quartzite / Granitic Gneiss)

Metamorphic Quartzite / Granitic Gneiss

Limonite Concretion

FeO(OH)·nH2O

Concrete-like aggregate surface with embedded rock fragments

Anthropogenic concrete or exposed aggregate; not a natural rock specimen

Amygdaloidal Basalt (or Orbicular/Vesicular Basalt)

Basalt with quartz/agate amygdules

Exposed Aggregate Concrete (Pea Gravel)

Concrete with Siliceous Alluvial Gravels

Undetermined Due to Blur (Possible Flesh-Tone Mineral)

Unknown (Insufficient Visual Clarity)

Mixed rock and mineral collection

Multiple specimens; visible pieces may include quartz, calcite, agate/chalcedony, jasper, and dyed or coated materials

Pumice

Pumice (Vesicular Felsic Igneous Rock)

Fossilized shell-bearing limestone

Bioclastic limestone, likely molluscan/coquina limestone (calcite, CaCO₃)

Tumbled translucent quartz or chalcedony fragment

Silicon dioxide, SiO₂; likely quartz/chalcedony

Generic Rock Fragment

Rock Fragment

Concrete aggregate surface

Human-made cementitious composite; primarily calcium-silicate-hydrate cement with mixed silicate aggregate

Quartz Veined Breccia

Tectonic Breccia with Quartz Cement

Riverstone (Sandstone Pebble)

Arenite (SiO2 with various lithic fragments)

Green cabochon gemstone pendant, likely turquoise or dyed green turquoise

Probably turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; exact identification requires testing

Limonite

FeO(OH)•nH2O