Minerals

Rock Specimen

Unclassified rock specimen

Fossil Shark Tooth

Odontaspididae (Sand Tiger Shark family)

Quartz–calcite sulfide-bearing mineral specimen

Quartz (SiO₂) with likely calcite (CaCO₃) and iron sulfides, possibly pyrite (FeS₂); exact species requires testing

Quartz Mineral

Silicon Dioxide (SiO2)

Weathered serpentinized ultramafic rock

Serpentinite; chiefly serpentine-group minerals, commonly with magnetite, brucite, talc, and relict olivine/pyroxene

Likely weathered granite or granitic gneiss

Quartz–feldspar–mica rock; possibly gneissic granite

Quartz-rich hydrothermal mineral specimen, possibly vanadinite-bearing matrix

Quartz (SiO₂) with unidentified red-brown accessory minerals; exact species requires testing

Pegmatite

Pegmatite (felsic intrusive igneous rock)

Weathered dark volcanic rock, possibly basalt

Basalt (tentative; likely iron-rich mafic volcanic rock)

Schist

Schist

Pink Granite

Granite (Phaneritic Quartz-Feldspar rock)

Gneiss

Gneiss (Metamorphic Rock)

Diorite

Phaneritic Intermediate Igneous Rock

Granite

Granite (Felsic Plutonic Rock)

Milky quartz

Quartz, silicon dioxide (SiO₂)

Lapis Lazuli

Na6Ca2(Al6Si6O24)(S,SO4,Cl)1-2 (primarily containing Lazurite with inclusions of Calcite and Pyrite)

Weathered basaltic river pebble

Basalt, likely altered or partially vesicular basalt

Gneiss

Gneiss

Fossilized Vertebra

Chordata fossil (Vertebra)

Tree Agate

Silicon dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Iron-Stained Quartz Pebble

Quartz (Silicon Dioxide, SiO2) with Iron Oxide Inclusion/Staining

Pegmatitic granite, strongly weathered

Granite/pegmatite composed mainly of quartz, feldspar, and mica

Milky quartz

Quartz (silicon dioxide, SiO₂)

Granite Gneiss

Gneiss (Derived from Granite protolith)

Nickel coin (U.S. currency)

Cupronickel (75% Copper, 25% Nickel alloy)

Schist

Mica Schist

Milky quartz

Quartz, silicon dioxide (SiO₂)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Shark Tooth Fossil

Vertebrate fossilized tooth

Banded gneiss pebble

Gneiss, composed chiefly of quartz, feldspar, and mica/amphibole

Limonite / Goethite (Iron Ore Mineral nodule)

FeO(OH)·nH2O / FeO(OH)

Vesicular basalt (scoriaceous basalt)

Basalt, primarily plagioclase, pyroxene, and iron-rich olivine; vesicular variety may be termed scoria

Ferruginous Sandstone (Gozzanous)

SiO2 (Quartz) with FeO(OH) (Goethite) or Fe2O3 (Hematite) coating

Vesicular basalt (likely weathered lava rock)

Basalt; chiefly plagioclase, pyroxene, and often olivine

Banded Metamorphic Rock

Gneiss or Schist

Likely weathered quartz-bearing rock fragment

Indeterminate; appears to contain quartz (SiO₂) with iron-oxide staining, possibly from quartzite, granite, or pegmatite

Schist (Greenschist / Mica Schist)

Metamorphic rock rich in platy minerals (e.g., Chlorite/Mica schist)

Weathered granite or granitic gneiss fragment

Quartz–feldspar–mica granite; possibly foliated granitic gneiss

Azurite and Malachite

Cu3(CO3)2(OH)2 (Azurite) and Cu2(CO3)(OH)2 (Malachite)

Gneiss

Gneiss (High-grade Metamorphic Rock)

Gneiss

Gneiss