Mineraloid

Dendritic Quartz

Silicon Dioxide (SiO2) with Manganese Oxide inclusions

Banded Calcite (Onyx Marble / Travertine)

Calcium Carbonate (CaCO3)

Tumbled kambaba jasper (likely)

Kambaba jasper, a silica-rich microcrystalline quartz aggregate, commonly containing fossilized cyanobacterial structures and dark green amphibole/pyroxene minerals

Blue-green raw mineral specimen, likely apatite

Fluorapatite, Ca₅(PO₄)₃F (probable; visual identification only)

Polished porphyritic volcanic rock, likely andesite or basalt

Porphyritic andesite/basalt; commonly plagioclase and pyroxene phenocrysts in a fine volcanic groundmass

Black volcanic rock, likely basalt

Basalt; primarily plagioclase feldspar and pyroxene, commonly with minor olivine or magnetite

Greenish weathered volcanic rock, likely altered basalt

Altered basalt/mafic volcanic rock; green coloration may reflect chlorite, epidote, or celadonite

Likely weathered basalt pebble

Basalt, a fine-grained mafic volcanic rock; commonly composed of plagioclase, pyroxene, and minor olivine

Granite

Intrusive igneous rock composed mainly of quartz, alkali feldspar, and plagioclase

Gneiss (specifically a granitic gneiss cobble)

Gneiss (high-grade regional metamorphic rock)

Carved amethyst fluorite (likely)

Amethyst, purple variety of quartz (SiO₂), possibly with fluorite (CaF₂)

Tumbled serpentine-rich altered rock

Serpentinite, likely antigorite/lizardite with accessory carbonate, quartz, or iron oxides

Likely graphite-rich schist (possibly galena-bearing metamorphic rock)

Graphite schist; chiefly quartz–mica with graphite (identification uncertain from photograph)

Unakite (likely)

Epidote–pink feldspar–quartz rock; commonly termed unakite

Rounded river pebble, likely quartz-rich stone

Unidentified lithic clast; exact mineralogy cannot be determined from the image

Likely iron-rich metamorphic rock (possibly hematite-rich ironstone)

Unidentified ferruginous rock; exact mineralogy cannot be determined from the image

Rounded iron-rich concretion or weathered lateritic pebble

Goethite/hematite-bearing ferruginous concretion; exact mineralogy requires testing

Concretion (likely iron-rich sandstone or claystone concretion)

Diagenetic carbonate/iron-oxide concretion; exact mineralogy requires testing

Desert Rose Fragment (Atypical) / Weathered Chert

Silicon Dioxide (SiO2) or Barium Sulfate (BaSO4) depending on exact mineralogy

Banded Gneiss

Gneiss (Metamorphic rock of variable mineralogy, often quartz-feldspar base)

Schist

Schist (various mineralogical compositions including mica, chlorite, talc, etc.)

Serpentine-rich greenstone (probable serpentine/soapstone fragment)

Serpentine-group minerals, chiefly antigorite/lizardite; possibly minor talc, chlorite, and carbonate

Tumbled green aventurine (likely)

Quartzite dominated by quartz (SiO₂), with green fuchsite mica inclusions

Polished labradorite

Labradorite, calcium-rich plagioclase feldspar; approximately (Ca,Na)(Al,Si)₄O₈

Polished serpentinite pebble

Serpentinite; primarily serpentine-group minerals (Mg3Si2O5(OH)4), with possible magnetite and talc

Polished pink-and-green feldspar-bearing rock, likely unakite or aventurine granite

Unakite-like epidote–feldspar–quartz aggregate; composition commonly K-feldspar + quartz + epidote

Quartz-bearing weathered rock

Massive to drusy quartz (SiO₂), possibly in a feldspathic or carbonate host

Altered volcanic rock, possibly andesite

Likely porphyritic andesite or dacite with secondary chlorite/epidote and quartz–calcite veins

Dark metamorphic rock, likely biotite schist or hornblende-bearing gneiss

Probable mica schist/amphibolite; composition may include biotite, amphibole, quartz, feldspar, and iron oxides

Tumbled quartz-rich pebble

Quartz (SiO₂), possibly iron-stained milky quartz or quartzite

Gold-bearing pyrite-rich rock (iron pyrite)

Pyrite, FeS₂, likely in a quartz- or sulfide-rich matrix

Weathered quartz-rich rock, likely quartzite or milky-quartz vein material

Quartzite (dominantly SiO₂), possibly quartz-vein breccia with iron-oxide staining

Iron-stained quartz-rich rock, likely pegmatite or quartz vein fragment

Quartz (SiO₂) with feldspar, mica, and iron-oxide/hydroxide staining; possibly weathered granite pegmatite

Red Granite

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

Red Granite

Phaneritic Plutonic Rock (High Potassium Feldspar)

Polished orbicular gabbro tower

Gabbro, likely orbicular/pegmatitic variety; mainly plagioclase feldspar and pyroxene, with possible amphibole, olivine, and magnetite

Brown chert or flint pebble

Microcrystalline quartz (SiO₂), commonly with chalcedony and iron-oxide staining

Rhyolite

Extrusive Felsic Igneous Rock

Weathered river pebble, likely quartz-rich sandstone or quartzite

Indeterminate; probable quartz (SiO₂)-rich sandstone/quartzite with iron-oxide staining

Likely serpentinite or serpentinized ultramafic rock

Serpentinite; chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), possibly with magnetite and minor olivine/pyroxene

Rounded greenstone cobble

Likely greenschist or altered basalt; composition commonly chlorite, epidote, actinolite, albite, and quartz

Granite

Intrusive Igneous Rock