Not A Rock Or Mineral (Anthropogenic Material)

Milky quartz in host rock

Quartz (SiO₂), likely a quartz vein or quartz-rich fragment

Porphyry (likely Porphyritic Andesite or Basalt)

Porphyritic Igneous Rock

Quartz in Matrix (possibly Basalt or Siltstone host)

Silicon Dioxide (SiO2) in Host Rock

Sandstone

Clastic Sedimentary Rock

Milky quartz vein rock

Quartz (SiO₂), likely in a quartz-rich host rock with minor iron-stained minerals

Painted Sandstone

Sandstone (clastic sedimentary rock) with acrylic/artistic coating

Sandstone (Banded)

Clastic Sedimentary Rock: Arenite

Tumbled dark-green stone, possibly serpentine

Undetermined; serpentine-group rock (predominantly serpentine minerals) is a tentative visual identification

Sandstone

Arenite (SiO2 principal composition)

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Thunderegg (Agate or Quartz Geode)

Silica-filled rhyolitic nodule (SiO2)

Sandstone

Arenite

Sandstone

Arenite (SiO2 based)

Polished red jasper (likely brecciated jasper)

Microcrystalline quartz/chalcedony, SiO₂, colored mainly by iron oxides

Quartz-veined Limestone

Sedimentary limestone with quartz/calcite veinlets

Carnelian agate

Cryptocrystalline quartz (SiO₂), iron-oxide-bearing chalcedony

Sandstone

Clastic Sedimentary Rock

Red jasper in gray host rock (likely hematite-stained quartzite or rhyolite)

Jasper: microcrystalline quartz (SiO₂), with iron-oxide coloration; exact host uncertain from image

Sandstone (Ferruginous)

Arenite (with Iron Oxide)

Rounded, banded metamorphic cobble

Likely gneiss or foliated quartz-rich metamorphic rock; exact identification is uncertain from the photograph.

Greenstone pebble (likely serpentinite)

Serpentinite, composed mainly of serpentine-group minerals

Sandstone (likely Greywacke or Lithic Sandstone)

Arenite / Wacke

Polished amber agate pendant/beads

Chalcedony (microcrystalline quartz), SiO₂, likely iron-stained yellow-orange agate

Foliated metamorphic rock, likely gneiss or schist

Quartz–feldspar–mica gneiss/schist; exact identification requires petrographic examination

Sandstone

Arenite

Sandstone

Arenite (primarily SiO2)

Gravel and Sediment Sample

Mixed clastic sediment

Likely amphibolite

Amphibolite, composed mainly of hornblende and plagioclase feldspar

Quartz Pebble

Silicon Dioxide (SiO2)

Green serpentine-rich rock (possibly serpentinite)

Serpentinite, composed chiefly of serpentine-group minerals (e.g., lizardite, antigorite, or chrysotile)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Sandstone

Clastic Sedimentary Rock

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)

Sandstone

Sedimentary Rock (Quartz Sandstone)

Mica-rich schist (likely biotite schist)

Biotite schist; quartz- and feldspar-bearing, with abundant mica

Quartz vein in dark host rock

Quartz (SiO₂), likely in basalt, gabbro, or altered mafic rock

Speckled feldspar-rich pebble

Likely leucocratic granite or granitic pegmatite, chiefly potassium feldspar with dark biotite or amphibole

Unidentified brown rock fragment

Not identifiable from the image; possibly iron-stained sandstone or another common weathered rock

Quartz-bearing pegmatitic rock, likely granite/pegmatite

Feldspar–quartz pegmatite; chiefly K-feldspar, plagioclase, quartz, and possible mica

Likely weathered iron-rich breccia or jasper

Silicified iron-oxide breccia; exact identification requires testing

Sandstone

Arenite (primarily SiO2)