Synthetic Material (Not A Rock Or Mineral)

Unidentified brown mineral/rock fragment

Indeterminate from image; possibly iron-stained quartz, feldspar, or weathered limonite

Sandstone

Arenite (Clastic Sedimentary Rock)

Fossilized shell fragment

Likely calcitic or aragonitic bivalve/gastropod shell; exact taxon indeterminate

Banded gneiss

Foliated gneiss, likely quartz–feldspar–biotite or amphibole gneiss

Sandstone (with Iron Staining)

Clastic Sedimentary Rock (primarily Quartz with Limonite/Goethite staining)

Sandstone (with potential fossil fragments)

Sandstone (SiO2 dominated with iron oxides)

Quartz-rich gravel fragment

Quartz (silicon dioxide, SiO₂), possibly with feldspar or carbonate inclusions

Ruby (Corundum)

Corundum (Aluminum Oxide) with chromium trace elements, Al2O3

Ruby

Corundum (Aluminium Oxide with Chromium impurities, Al2O3:Cr)

Unidentified gray rock fragment

Indeterminate from image; possibly quartz- or feldspar-rich silicate material

Grass (Organic Matter/Soil)

Poaceae (family of monocotyledonous flowering plants)

Epidote-rich rock (likely epidotite or altered basalt)

Epidote, Ca₂(Al,Fe³⁺)₃(SiO₄)₃(OH); possibly epidote-bearing mafic rock

Sandstone

Clastic Sedimentary Rock

Dalmatian jasper

Quartz-bearing alkali feldspar syenite/porphyritic igneous rock, commonly marketed as Dalmatian jasper

Sandstone

Clastic Sedimentary Rock

Sandstone

Arenite (primarily Quartz, SiO2)

Blue gemstone ring, likely sapphire

Corundum, Al₂O₃ (probable blue sapphire); surrounding stones may be diamonds or simulants

Quartz vein in host rock

Milky quartz (SiO₂) with likely metamorphic country rock, possibly gneiss or schist

Sandstone

Arenite (Clastic Sedimentary Rock)

Blue Sapphire

Corundum (Al2O3) with traces of Iron and Titanium

Quartz in Matrix (possibly Basalt or Siltstone host)

Silicon Dioxide (SiO2) in Host Rock

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Sandstone (Iron-stained)

Arenite (primarily SiO2 with Fe2O3 staining)

Sandstone (Pebble)

Arenite (SiO2 based)

Asphalt Concrete

Bituminous conglomerate

Diamond

Pure Carbon (C)

Emerald

Beryl (Be₃Al₂Si₆Oထ₈) with Chromium/Vanadium impurities

Sandstone

Arenite (SiO2 composed primarily of quartz)

Polished red jasper (likely brecciated jasper)

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

Porphyry (likely Porphyritic Andesite or Basalt)

Porphyritic Igneous Rock

Tumbled dark-green stone, possibly serpentine

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

Sandstone

Sedimentary Rock (Quartz arenite)

Turquoise jewelry beads/earrings

Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O; possibly reconstructed or imitation turquoise

Blue sapphire ring

Corundum, aluminum oxide (Al₂O₃), blue variety colored mainly by iron and titanium

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

Thunderegg (Agate or Quartz Geode)

Silica-filled rhyolitic nodule (SiO2)

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Carnelian agate

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

Rounded, banded metamorphic cobble

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

Smoky Quartz

Silicon Dioxide (SiO2)