Mineral, Possibly Rock Fragment Containing A Mineral

Quartz-rich breccia or vein quartz with dark inclusions

Milky quartz (SiO₂), likely brecciated and cemented with iron oxides and dark mica/amphibole minerals

Sandstone (Pebble)

Clastic sedimentary rock (SiO2 primary)

Tumbled brown translucent mineral fragment

Indeterminate; possibly quartz/chalcedony or weathered feldspar

Amygdaloidal Basalt

Amygdaloidal Basalt (with secondary mineral infilling)

Decorative mosaic cross containing mixed rock and glass fragments

Polychrome aggregate; likely quartz, feldspar, marble, granite, and assorted colored glass

Likely milky quartz-bearing rock

Quartz, silicon dioxide (SiO₂), possibly in a quartz-rich vein or sugary quartzite

Likely weathered sandstone or iron-rich sedimentary rock

Quartz-rich sandstone, possibly ferruginous sandstone

Possible green tourmaline (small rough crystal fragment)

Possibly elbaite, Na(Li₁.₅Al₁.₅)Al₆(Si₆O₁₈)(BO₃)₃(OH)₄; identification is uncertain from the blurry image

Likely pyrite-bearing rock or pyrite fragment

Pyrite (FeS₂), possibly mixed with quartz or carbonate matrix

Dark igneous rock, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and possibly olivine

Weathered quartz-rich pebble, possibly quartzite or granite fragment

Quartzite (mostly SiO₂), though the specimen may contain feldspar and other silicates

Weathered quartz-rich stone, likely milky quartz

Quartz (SiO₂), possibly a quartz-rich metamorphic or igneous fragment

Sandstone (River Cobble)

Clastic Sedimentary Rock (primarily Quartz with Feldspar)

Granite

Intrusive igneous rock

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Fossilized Bone

Petrified Bone (Fluorapatite / Calcium Phosphate replacement)

Amygdaloidal Rhyolite

Amygdaloidal felsic extrusive rock

Brachiopod Fossil in Matrix

Phylum Brachiopoda

White quartz-rich rock, likely quartzite or milky quartz fragment

Quartzite; predominantly quartz (SiO₂), possibly with minor feldspar or mica

Polished agate or jasper fragment

Microcrystalline quartz (chalcedony), SiO₂, possibly iron-oxide-rich

Granite or granitic rock fragment

Felsic intrusive igneous rock, typically quartz + feldspar + mica; exact species uncertain from the image

Gneiss or Schist

Gneiss or Mica Schist with Garnet

Iron-rich breccia or weathered ironstone

Goethite–hematite-bearing limonite, possibly with quartz and altered rock fragments

Rhyolite (iron-stained, weathered volcanic rock)

Rhyolite; chiefly quartz and alkali feldspar with minor plagioclase, biotite, and iron oxides

Banded gneiss

Foliated silicate rock, typically quartz–feldspar–mica gneiss

Rhyolite with Lithophysae and Iron Oxide

Extrusive igneous rock / Felsic volcanic rock

Sandstone (lithic/greywacke variety)

Arenite (composed primarily of SiO2 with various lithic fragments)

Possible iron-rich pebble with a weathered inclusion

Unidentified; image alone does not support a reliable mineral or rock identification

Weathered brown rock fragment

Indeterminate; possibly iron-stained sandstone or weathered limestone

Polished dark granitoid pebble

Likely basalt or fine-grained gabbro; chiefly plagioclase and pyroxene, possibly magnetite

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Blue glassy mineral fragment (possibly turquoise)

Unidentified blue mineral; turquoise is hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Quartz geode

Quartz (SiO₂), likely a chalcedony-lined geode with drusy quartz crystals

Vesicular basalt (likely weathered lava rock)

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

Tumbled green-blue glassy mineral, possibly fluorite or aventurine

Uncertain from image; possible fluorite (CaF₂) or quartz aventurine (SiO₂)

Tumbled dark pebble

Indeterminate; likely basalt or fine-grained dark metamorphic rock

Likely weathered granite or granitic gneiss fragment

Quartz–feldspar–mica aggregate; possibly biotite granite or granitoid gneiss

Granite

Intrusive Igneous Rock

Basalt with Phenocrysts

Extrusive Igneous Rock

Quartz vein rock

Milky quartz (SiO₂) in altered host rock, likely quartz-bearing hydrothermal breccia

Weathered gray mineral-rich rock, possibly galena-bearing ore

Tentatively galena-bearing sulfide vein rock; galena is PbS, but identification is uncertain from the photograph

Rounded iron-rich pebble, possibly weathered laterite or ironstone

Ironstone/lateritic ferricrete; predominantly goethite–hematite with clay and quartz impurities