Mineralological Specimen

Bivalve Fossil (Shell-bearing Sedimentary Rock)

Class Bivalvia (Phylum Mollusca) within a Calcarenite/Sandstone matrix

Quartz with Epidote

Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate [Ca2(Al,Fe)3(SiO4)3(OH)]

Chert (with Desert Varnish/Iron Stain)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Rough quartz-rich rock, possibly granite or pegmatite

Likely quartz and feldspar with possible mica; exact rock type cannot be determined from the image

Quartz-rich rock, possibly milky quartz with iron staining

Predominantly silicon dioxide (SiO₂); exact rock type cannot be determined from the photo

Ironstone concretion (possibly limonite/goethite-bearing)

Limonite, a mixture of hydrated iron oxides, commonly including goethite (α-FeO(OH))

Diamond (Cut Specimen)

Carbon (C)

Reddish-brown crystalline rock, possibly weathered granite or garnet-bearing schist

Indeterminate; likely quartz–feldspar–mica rock with iron oxides, potentially garnet-bearing

Weathered quartz-rich pebble, possibly granitic gneiss

Quartz–feldspar–mica aggregate; likely granitoid or gneiss

Likely tumbled or polished fossil shell

Fossilized mollusk shell; exact species cannot be determined from this image

Possible basalt or other dark volcanic rock

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

Dark gray crystalline rock, possibly mica-rich schist or graphite-bearing gneiss

Indeterminate; likely quartz–feldspar–mica metamorphic rock

Pink-gray granite

Granite; chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende

Likely magnetite-bearing rock

Magnetite (Fe₃O₄), possibly in a mafic host rock

Travertine (Tufa)

Chemical Sedimentary Rock / Travertine (CaCO3)

Orthoclase (Potassium) Feldspar in Quartz

KAlSi3O8 (Potassium Aluminum Silicate)

Amethyst

Amethyst (Silicon Dioxide - SiO2 with impurities of iron)

Chalcedony (Desert Rose or Botryoidal Chalcedony)

Silicon Dioxide (SiO2)

Silver (Native Element)

Ag (Argentum) - 90% Silver, 10% Copper alloy in specimen

Blue calcite (rough fragment)

Calcite, CaCO₃

Limonite

FeO(OH)•nH2O

Clear gemstone earring (likely cubic zirconia)

Cubic zirconia (synthetic zirconium dioxide, ZrO₂); identification from the image is uncertain

Likely basalt or other fine-grained volcanic rock

Basalt (tentative; image alone is insufficient for a firm identification)

Iron-stained quartz-rich rock

Likely ferruginous quartzite; chiefly quartz (SiO₂) with iron oxides/hydroxides

Gold-bearing quartz sulfide specimen

Native gold (Au) with quartz (SiO₂), likely associated with iron sulfides such as pyrite

Conglomerate

Sedimentary Conglomerate with Basaltic Clast

Polished labradorite

Labradorite, a plagioclase feldspar in the albite–anorthite series (approximately (Ca,Na)(Al,Si)₄O₈)

Basalt River Cobble

Basalt (Aphanitic Mafic Volcanic Rock)

Banded Chert

Silicon Dioxide (SiO2)

Chert (potentially Jasper or Agatized Chert)

Microcrystalline Quartz (SiO2)

Banded agate (chalcedony)

Microcrystalline quartz (SiO₂), variety chalcedony

Possibly garnet-bearing rock fragment

Unidentified reddish-brown mineral or rock; the image is insufficient for a reliable species identification.

Dark mafic rock, likely altered basalt or gabbro

Fine- to medium-grained mafic silicate rock; probable basaltic composition with plagioclase and pyroxene, possibly chloritized/serpentinized

Galena-bearing sulfide specimen

Galena (PbS), likely with sphalerite and/or pyrite gangue

Clear Quartz (Rock Crystal) Bead

Silicon Dioxide (SiO2)

Biotite (Black Mica)

Biotite (K(Mg,Fe++)3AlSi3O10(OH,F)2)

Limonite

FeO(OH)·nH2O

Granite

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

Quartz Pebble (Iron-Stained)

Silicon Dioxide (SiO2)

White Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Jasper and Quartzite Breccia

Silicified sedimentary breccia