Not A Rock (Synthetic Material)

Man-made Blank Ammunition (Brass)

CuZn (Cartridge Brass - roughly 70% Copper, 30% Zinc)

Limestone (Weathered)

Sedimentary Carbonate Rock (CaCO3)

Sandstone

Arenite (SiO2 based)

Diamond (Rough)

Diamond (Carbon, C)

Sandstone

Quartz Sandstone (predominantly)

Sandstone

Arenite (SiO2 predominantly)

Sandstone

Arenite (primarily Quartz and Feldspar)

Sandstone

Arenite (SiO2 based)

Sandstone / Chert Gravel

SiO2 (Silicon Dioxide based clastic sedimentary rock)

Sandstone with Dendritic Inclusions

Quartzose Sandstone

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

Silicified limestone or banded sedimentary rock with mineral veins

Sandstone

Sandstone (Siliciclastic Sedimentary Rock)

Granite Cobble / Gneiss (River Rock)

Granitic Gneiss / Felsic Igneous Rock

Fossil Coral

Rugosa or Tabulata coral fossil (Calcium Carbonate, CaCO3)

Sandstone (Red)

Arenite (composed primarily of SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide cement)

Sandstone

Arenite (Clastic Sedimentary Rock)

Siltstone Pebble

Siltstone (fine-grained siliciclastic sedimentary rock)

Sandstone

Arenite

Mixed rock collection

Labeled specimens appear to include iron-rich rock, schist, basalt, serpentinite, and shale

Granitic Pebble (Glacial Erratic)

Granite

Green glassy slag (often sold as “sea glass” or “green obsidian”)

Industrial vitreous slag; primarily amorphous silicate glass, composition variable

River Pebble (Gravel)

Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)

Sandstone (Ferruginous)

Arenite (SiO2 with iron oxide impurities)

Tumbled dark volcanic rock, possibly basalt

Basalt; commonly composed of plagioclase feldspar, pyroxene, and minor olivine or magnetite

Likely weathered vesicular volcanic rock

Probable basaltic scoria or vesicular andesite; exact identification requires testing

Rounded pebble, likely quartz-rich

Undetermined quartz-rich lithic pebble; exact rock type cannot be identified from the photograph

Greenish altered rock, possibly serpentinite or chlorite-rich schist

Tentative: serpentine-group minerals, chiefly antigorite/lizardite, or chlorite–actinolite assemblage

Dalmatian jasper

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

Green glassy mineral specimen, likely rough emerald or green fluorite

Tentatively beryl (Be₃Al₂Si₆O₁₈), emerald variety; synthetic/man-made glass cannot be excluded from the photograph

Turquoise ring (likely stabilized or imitation turquoise)

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; exact material is uncertain from the image

Moonstone

Orthoclase (Potassium Aluminum Silicate), Formula: (K,Na)AlSi3O8

Lapis Lazuli

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

Sandstone

Sandstone (Quartz-rich Arenite / SiO2)

Granite

Granite

Pumice or Scoria

Vesicular volcanic rock

Serpentinite

Serpentinite (a rock composed predominantly of serpentine group minerals)

Granite

Felsic intrusive igneous rock

Sandstone (with Moss)

Quartz Arenite / Sandstone

Mixed rounded river pebbles

Polymictic alluvial gravel; likely quartz/quartzite, chert, and weathered feldspathic rocks

Sandstone or similar clastic rock

Arenite

Asphalt Concrete (Bituminous Conglomerate)

Anthropogenic Bituminous Conglomerate