Mineral Specimen

Chrysocolla

Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O

Quartz Pebble

Silicon Dioxide (SiO2)

Banded Calcite (Honey Calcite)

Calcium Carbonate (CaCO3)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Chalcedony (Variety: Agate)

Silicon Dioxide (SiO2)

Quartz (Small Fragment)

Silicon Dioxide (SiO2)

Quartz (Small Fragment)

Silicon Dioxide (SiO2)

Blue Agate (Dyed)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Botryoidal chalcedony (likely white quartz/chalcedony)

Microcrystalline quartz, SiO₂; possibly partly altered carbonate or opaline silica

Likely metallic sulfide mineral fragment

Possibly galena (PbS) or pyrite (FeS₂); identification is uncertain from the photograph

Quartz (Clear Quartz)

Silicon Dioxide (SiO2)

Tumbled pale green aventurine (probable)

Quartz, SiO₂, with dispersed fuchsite or other green inclusions

Tumbled brecciated jasper

Silica-rich microcrystalline quartz/chalcedony (SiO₂), with iron-oxide and other mineral inclusions

Blue Agate Geode Slice

Silicon Dioxide (SiO2) - Chalcedony variety

Gold

Native Gold (Au)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Agate (or Operculum / Fossil Shell)

Silicon Dioxide (SiO2)

Bloodstone

Heliotrope (Chalcedony)

Quartz (Milky to Clear)

Silicon Dioxide (SiO2)

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

Sandstone or Quartzite

Arenite (if sedimentary) / Quartzite (if metamorphic)

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Sandstone

Arenite (primarily composed of SiO2)

Dendritic Quartz

Silicon Dioxide with inclusions (SiO2)

Chert (Banded)

Cryptocrystalline Silica (SiO2)

Quartz / Feldspar Specimen

SiO2 (Quartz) / KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8 (Feldspar Group)

Obsidian

Extrusive igneous volcanic glass (rich in SiO2)

Green Aventurine

Silicon Dioxide with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)

Quartz with Chalcopyrite and Pyrite

Silicon Dioxide (SiO2) with Copper Iron Sulfide (CuFeS2)

Gabbro with Quartz Vein

Gabbro (mafic intrusive igneous rock)

Ferruginous Sandstone (with possible Epidote/Chlorite coloring)

Sandstone (SiO2 dominated with Fe2O3 staining)

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Quartz with Mica inclusions (likely Schist or Gneiss host)

Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(OH)2)

Sandstone (Banded)

Arenite

Sandstone (Quartzite-rich River Cobble)

Clastic sedimentary rock (primarily SiO2)

Moonstone (specifically Rainbow Moonstone / White Labradorite)

White Labradorite (Feldspar Group: (Na,Ca)(Al,Si)4O8)

Granite Pebble (Pegmatitic Quartz-Feldspar River Rock)

Granite / Quartz-Feldspar-Mica Aggregate

Clear Quartz (Tumbled)

Silicon Dioxide (SiO2)

Chalcedony (River Stone)

Silicon Dioxide (SiO2)