Synthetic Material (Not A Rock Or Mineral)

Smooth gray pebbles

Unidentified rounded rock fragments; composition cannot be determined from the image

Lapis Lazuli

Lapis lazuli (complex rock; primarily Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Quartz Vein in Siltstone

Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix

Sandstone

Clastic Sedimentary Rock

Likely bituminous coal

Coal, predominantly carbon-rich organic matter with variable maceral and mineral content

Lazulite Quartzite

Quartzite with Lazulite (SiO2 with (Mg,Fe)Al2(PO4)2(OH)2)

Jasper and Epidote in Quartzite

Metamorphic rock containing microcrystalline quartz, epidote, and jasper

Opalite (a synthetic glass, often confused with Opal)

Silicon dioxide glass (SiO2nH2O, for natural opal)

Lapis Lazuli

A metamorphic rock primarily composed of lazurite (Na,Ca)8[(S,SO4,Cl)2|(Al6Si6O24)], calcite (CaCO3), and pyrite (FeS2).

Unidentified rock fragments

Indeterminate; likely a weathered, iron-stained silicate rock

Red Sandstone

Arenite (SiO2 with Fe2O3)

Quartz vein in Schist

Crystalline Silicon Dioxide (SiO2) in Metamorphic Host

Sandstone

Clastic sedimentary rock (Quartz arenite)

Weathered stone nodule or concretion

Unidentified lithic concretion; composition cannot be determined from the image

Schist

Mica Schist

Unidentified pale mineral or rock surface

Indeterminate from image; possibly a small quartz or feldspar grain

Likely polished or naturally smoothed pebble with a pale mineral patch

Undetermined; possibly a dark volcanic rock with a quartz or feldspar inclusion

Sandstone (with Moss)

Quartz Arenite / Sandstone

Vesicular volcanic rock, likely scoria

Scoria; composition commonly basaltic to andesitic, rich in plagioclase and pyroxene

Likely blue sapphire ring

Corundum (Al₂O₃), likely sapphire; surrounding stones may be diamonds or colored gems

Faceted yellow gemstone ring

Likely yellow sapphire (corundum), but exact identification requires testing; alternatives include citrine, chrysoberyl, or treated diamond.

Sandstone

Clastic sedimentary rock

Banded Sedimentary Rock (Wishbone Stone / Banded Quartzite or Limestone)

Silicified limestone or banded sedimentary rock with mineral veins

Sandstone

Arenite (SiO2 principal)

Red Sandstone

Arenite (Iron-rich)

Green Fluorite (likely synthetic or heat-treated for jewelry)

Calcium Fluoride (CaF2)

Red gemstone ring, likely synthetic ruby

Corundum (Al₂O₃), chromium-bearing; possibly lab-created ruby or red glass imitation

Diamond (or Clear Quartz / Cubic Zirconia)

Carbon (C) or Silicon Dioxide (SiO2) / Cubic Zirconia (ZrO2)

River cobble (Greywacke/Sandstone)

Sandstone / Greywacke

Quartz-rich geode or mineralized cavity in host rock

Likely a quartz-bearing geode; the pale crystals may be quartz (SiO₂), but the photo is not detailed enough for a firm identification.

Opal

Hydrated amorphous form of silica (SiO2·nH2O)

Hematite

Iron(III) oxide (Fe2O3)

Greenish metamorphic rock (possibly chlorite schist)

Chlorite-rich schist; exact identification is uncertain from the image

Polished dark agate or jasper specimen

Cryptocrystalline quartz (chalcedony), SiO₂; exact identification is uncertain from the image

Sandstone (Wonderstone)

Clastic Sedimentary Rock (primarily SiO2)

Tumbled turquoise

Turquoise, hydrated copper aluminum phosphate — CuAl₆(PO₄)₄(OH)₈·4H₂O

Decorative polished pebbles

Likely mixed quartz-rich lithologies, including quartzite, jasper, and/or basalt

Polished blue chalcedony or glass-like quartz specimen

Chalcedony (microcrystalline SiO₂), possibly treated or synthetic; exact identification requires testing

Probable fossil-bearing rock or mineral concretion

Unidentified carbonate-rich concretion with a possible fossil inclusion

Quartz Pebble with Drusy/Crystalline Pocket

Silicon Dioxide (SiO2)

Sandstone

Arenite (primarily SiO2)

Oak-grain Laminate (Industrial/Decorative Furniture Finish)

Melamine Resin-impregnated Decorative Paper on Particleboard (Cellulose/Thermosetting Plastic)