Igneous, Metamorphic, And Sedimentary (Mixed Assemblage)

Crushed Stone / Gravel

Aggregate (mixed lithology)

Gravel and Sediment Sample

Mixed clastic sediment

Smoky Quartz with Feldspar

SiO2 (Quartz) with KAlSi3O8 (Feldspar)

Weathered granitic rock fragment

Granite, predominantly quartz–feldspar–mica assemblage

Polished mixed rock, likely orbicular/epidote-bearing granite or basalt

Uncertain; probable quartz–feldspar–amphibole/epidote aggregate

Clear Quartz

SiO2 (Silicon Dioxide)

Weathered basaltic rock

Basalt, likely altered/vesicular basalt (plagioclase–pyroxene–olivine assemblage)

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Faceted Clear Quartz or Diamond Simulant

Silicon Dioxide (SiO2) if Quartz or Cubic Zirconia (ZrO2) if Synthetic

Weathered volcanic rock, likely altered basalt

Basaltic rock, probably chlorite–epidote–iron-oxide altered basalt

Crushed Granite and Quartz Gravel

Composite Igneous and Silicate Rock Aggregate

Ruby zoisite (anyolite) beads

Ruby-bearing zoisite; zoisite Ca₂Al₃(SiO₄)₃(OH), with corundum ruby Al₂O₃

Weathered granitic rock fragment

Likely granite or granodiorite, composed mainly of quartz, feldspar, and mica

Mixed stone-bead bracelet, likely agate/jasper and possibly sodalite or dyed quartz

Primarily microcrystalline quartz (SiO₂) varieties, with opaque iron-rich chalcedony/jasper and probable blue sodalite or dyed material

River Pebbles (Mixed Suite)

Mixed lithologies: Quartzite and Gneiss

Black Tourmaline

Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Weathered conglomeratic volcanic rock

Likely basaltic volcanic breccia or agglomerate, with plagioclase, pyroxene, volcanic glass, and lithic fragments

Small quartz-rich mineral fragment

Quartz (SiO₂), possibly milky or chalcedonic quartz

Jasper and Quartz Breccia

Silica breccia (SiO2)

Weathered granite cobble

Granite, typically quartz–feldspar–mica assemblage

Unakite

Unakite (altered granite)

Unakite

Epidotized Granite

Iron-rich concretion or weathered limonite/goethite nodule

Limonite (hydrous iron oxides), commonly dominated by goethite (FeO(OH))

Weathered porphyritic volcanic rock (likely basaltic andesite)

Porphyritic basaltic andesite; mineral assemblage likely plagioclase, pyroxene, and iron oxides

Mixed river-worn rock collection

Uncertain; likely quartzite, sandstone, basalt, and weathered granite or gneiss

Quartz with Mica inclusions (Pegmatite)

Silicon Dioxide (SiO2) with Muscovite/Biotite inclusions

Yellow Apatite

Fluorapatite (Ca5(PO4)3(F,Cl,OH))

Chert Arrowhead

Microcrystalline Quartz (SiO2)

Green Aventurine

SiO2

Weathered metallic sulfide-bearing rock, possibly schist or gneiss

Indeterminate; likely mica-rich metamorphic rock with iron sulfides or magnetite

Mixed rock and mineral specimens

Predominantly quartz-rich rocks, with a possible malachite-bearing specimen; exact identification is uncertain from the image

Mixed Gravel and Pebbles

Polylithic Alluvial Aggregate

Magnetite sand (black iron-oxide sand)

Magnetite, Fe₃O₄; commonly mixed with ilmenite and other heavy minerals

Apatite

Calcium phosphate fluoride/chloride, Ca5(PO4)3(F,Cl,OH)

Costume Jewelry Gemstones (Emerald-imitation and semi-precious beads)

BeCuAl6Si6O18 (Beryl structure), frequently simulated by glass or synthetic spinel

Mixed rounded fieldstones, likely granite and gneiss

Granite (quartz–feldspar–mica) and gneiss; exact identification is uncertain from the photograph

Pink Granite

Granite (Felsic Plutonic Rock)

Black Tourmaline (Schorl)

NaFe3Al6(BO3)3Si6O18(OH)4

Tumbled green jasper (probable serpentine-rich stone)

Jasper, microcrystalline quartz (SiO₂), possibly mixed with serpentine or chlorite

Mixed tumbled gravel and quartz-rich sandstone

Primarily quartz (SiO₂), feldspar, and lithic sedimentary fragments; one piece appears to be quartz-rich sandstone

Pyrite in Matrix (Fool's Gold)

Iron Sulfide (FeS2)

Banded iron formation (ironstone)

BIF; hematite–magnetite–quartz/chert assemblage