Mineralogical Specimen

Ocean Jasper (Orbicular Jasper)

Silica (SiO2) with varied mineral inclusions

Potassium feldspar

Orthoclase or microcline; KAlSi₃O₈

Biotite-rich schist

Mica schist; predominantly biotite mica with quartz and feldspar

Graphite-bearing quartz-mica schist

Graphite-rich quartz–mica schist; primarily quartz (SiO₂), muscovite/biotite, and graphite (C)

Weathered rhyolitic tuff or altered volcanic rock

Felsic volcanic tuff, likely devitrified or hydrothermally altered

Basalt with Plagioclase Phenocrysts

Porphyritic Basalt

Quartzite

Quartzite (primarily SiO2)

Diorite

Diorite (Intermediate intrusive igneous rock)

Amphibolite

Amphibolite (rich in amphibole and plagioclase feldspar)

Gneiss

High-grade Metamorphic Gneiss

Red Granite

Phaneritic Felsic Intrusive Igneous Rock (primarily K-feldspar, Quartz, and Biotite)

Quartzite

Quartzite (SiO2)

Granite

Phaneritic Igneous Rock (Granite)

Mixed mineral and shell specimen assortment

Primarily unidentified quartz-/feldspar-like pebbles with possible dark basalt or iron-rich fragments; white pieces may include shell or calcite

Weathered brown rock fragment, possibly iron-rich sandstone or altered basalt

Indeterminate; likely an iron-oxide–stained silicate rock

Small blue-green mineral or stone bead

Unidentified opaque blue-green mineral; the image is insufficient for reliable species identification

Pistachio-green and dark mineral-bearing rock, possibly serpentine with dark inclusions

Undetermined; the image is insufficient for reliable species-level identification

Dalmatian jasper (often sold as Dalmatian stone)

Quartz-bearing microgranular felsic rock, commonly an altered rhyolite or related volcanic rock with black aegirine/arfvedsonite-group inclusions

Small tumbled stone, likely quartz-rich pebble

Probably microcrystalline quartz (SiO₂), but the image is insufficient for a definitive identification

Flint or chert fragment

Microcrystalline quartz (SiO₂), commonly termed chert or flint

Small rounded stone or mineral fragment

Indeterminate; likely a common quartz- or feldspar-bearing silicate fragment

Sphalerite with quartz

Sphalerite (ZnS), associated with quartz (SiO₂)

Tumbled serpentine or chlorite-rich pebble

Serpentine-group minerals, chiefly antigorite/lizardite; possibly chlorite or greenstone

Weathered greenish rock fragment

Indeterminate; possibly epidote- or chlorite-bearing altered silicate rock

Unidentified purple mineral fragment

Possibly amethyst (quartz), but the image is insufficient for confident identification

Weathered greenish-brown rock, likely serpentinized ultramafic rock

Serpentinite; chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), possibly with olivine, pyroxene, magnetite, or carbonate

Iron Slag

Iron smelting byproduct (Glassy/vesicular silicate)

Tumbled green aventurine (probable)

Quartz (SiO₂), commonly with fuchsite mica inclusions

Dalmatian jasper

Orbicular rhyolite, commonly sold as Dalmatian jasper; quartz- and feldspar-rich volcanic rock with dark amphibole/biotite inclusions

Tiger's Eye (with Hematite/Jasper)

SiO2 (Silicon Dioxide) with Fe2O3 (Hematite)

Bismuth crystal

Bismuth (Bi), commonly laboratory-grown

Tumbled green jasper or serpentine

Jasper: microcrystalline quartz (SiO₂); possible serpentine: Mg₃Si₂O₅(OH)₄

Polished purple chalcedony (likely lavender agate)

Microcrystalline quartz, SiO₂; chalcedony variety, possibly naturally iron- or manganese-colored

Greenstone / altered mafic rock

Likely chlorite–actinolite schist or metabasalt; exact identification requires testing

Pink Granite

Potassium Feldspar-Rich Granite

Copper-bearing rock, likely native copper in a weathered matrix

Native copper (Cu), tentatively with copper sulfide/oxide minerals

Tumbled brown-and-black stone, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly plagioclase, pyroxene, and possibly olivine or iron oxides

Polished amber

Fossilized tree resin (primarily organic polymerized diterpenes)

Small brown-gray mineral fragment

Indeterminate; possibly weathered quartz-, feldspar-, or iron-oxide-bearing rock

Weathered volcanic rock fragment

Indeterminate fine-grained mafic-to-intermediate igneous rock; possibly andesite or basalt

Serpentinized ultramafic rock (serpentinite)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite, olivine, pyroxene, and brucite

Dalmatian jasper (often sold as Dalmatian stone)

Porphyritic alkali feldspar–quartz syenite, commonly with black arfvedsonite/aegirine-group amphibole inclusions