Mineralogical Specimen

Fluorite specimen

Fluorite (calcium fluoride, CaF₂)

Calcite specimen

Calcite (calcium carbonate, CaCO₃)

Calcite specimen

Calcite (calcium carbonate, CaCO₃), likely crystalline limestone or cave-calcite aggregate

Unidentifiable Specimen

Undetermined

Weathered schist or phyllite

Mica schist/phyllite; quartz–mica-rich foliated metamorphic rock

Polished Unakite pebble

Unakite: pink potassium feldspar and green epidote in quartz-rich rock

Vesicular basalt (scoria-like volcanic rock)

Basalt, composed mainly of plagioclase, pyroxene, and olivine; abundant vesicles formed by trapped gas

Unidentified weathered rock, possibly quartz-bearing granite or rhyolite

Indeterminate; likely quartz–feldspar-rich silicate rock

Weathered basaltic volcanic rock

Likely vesicular basalt or basaltic-andesite; chiefly plagioclase, pyroxene, and iron-bearing minerals

Gold Leaf in Glass Vial

Gold (Au)

Chert (Arrowhead/Scraper Preform)

Silicon dioxide (SiO2)

Biotite-bearing granite or granitic gneiss

Quartz–feldspar–biotite granite; possibly weakly foliated granitic gneiss

Sandstone with Quartz Vein

Arenite with SiO2 intrusion

Clear Quartz Crystal (Likely Golden Healer/Iron-Stained)

Silicon Dioxide (SiO2)

Likely calcite-rich limestone or marble

Calcite (CaCO₃); possibly recrystallized limestone (marble)

Quartz Vein in River Siltstone

Crystalline Quartz (SiO2) in Siliclastic Matrix

Vuggy Limestone

Carbonate Sedimentary Rock with Vuggy Porosity (CaCO3)

Orange Calcite

Calcium Carbonate (CaCO3)

Shale (with Iron Staining)

Argillaceous mudstone / Shale

Chert (Chalcedony)

Cryptocrystalline Quartz (SiO2)

Blue Grey Agate Geode

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Quartz Vein in Matrix

Silicon Dioxide (SiO2) within Rhyolitic or Granitic Matrix

Quartz geode or drusy quartz cluster

Quartz (silicon dioxide, SiO₂), likely a quartz-lined cavity in host rock

Weathered dark metamorphic rock, likely slate or phyllite

Fine-grained foliated rock, probably slate/phyllite; exact identification requires testing

Tumbled red jasper and blue-green turquoise (likely dyed or stabilized)

Red jasper: microcrystalline quartz, SiO₂, colored by iron oxides; turquoise: hydrated copper-aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Fossil scallop shell

Fossilized bivalve mollusk; likely Pectinidae or a related pectinid

Chalcopyrite

CuFeS2 (Copper Iron Sulfide)

Not a rock, mineral, or geological specimen

Uncertain polished mineral specimen

Indeterminate; possibly quartz or feldspar with iron-oxide staining

Amethyst druzy on agate/geode matrix

Quartz, SiO₂; purple coloration from trace iron and irradiation, with chalcedony (microcrystalline quartz) matrix

Quartz-rich conglomeratic sandstone

Lithic arkose/conglomerate, dominated by quartz and feldspar grains

Limonitic Sandstone with Inclusion

Limonitic Quartz Sandstone (primarily SiO2 with FeO(OH)·nH2O)

Quartzite with Hematite staining

Quartzite (SiO2)

Jasper

Silicon Dioxide (SiO2) with impurities

Chert (Jasper and Chalcedony)

Silicon Dioxide (SiO2)

Cobalt Blue Glass / Cullet Glass

Silicon dioxide (Amorphous man-made glass)

Small dark rock, possibly basalt or a weathered pebble

Unidentified specimen; basalt is a possible visual match, but the image lacks diagnostic detail

Lemon (Mock specimen mimicking Citrine/Sulfur)

Citrus x limon

Glauconitic Sandstone (or Greenstone)

Glauconitic Sandstone with Quartz

Common Opal / Chert

Hydrated silica (SiO2·nH2O) or Microcrystalline Quartz (SiO2)

Opal

Hydrated Silica (SiO2·nH2O)

Dark mafic rock, likely basalt

Basalt; primarily plagioclase feldspar, clinopyroxene, and possibly olivine