Man Made Material (Anthro Lithic Product)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Polished magnetite-rich rock, likely magnetite-bearing schist or ironstone

Magnetite (Fe₃O₄) in a foliated silicate matrix; exact identification requires testing

Quartzwacke / Impure Sandstone

Arenite with minor lithic fragments (Silicon Dioxide matrix)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Weathered granite or granitic gneiss

Granite, chiefly quartz–feldspar–mica; possibly weakly gneissic

Iron-stained weathered pebble

Likely ferruginous sandstone or iron-rich chert; exact identification requires testing

Fossil shell fragment (likely bivalve)

Bivalvia indeterminate; shell material chiefly aragonite or calcite (CaCO₃)

Tumbled milky quartz pebble

Quartz (SiO₂), likely massive milky quartz

Red vesicular basalt (tumbled volcanic rock)

Vesicular basalt; predominantly plagioclase, pyroxene, and iron-rich olivine

Limestone

Calcium Carbonate (CaCO3)

Chert (Flint)

Silicon Dioxide (SiO2)

Tumbled cream-colored pebble

Likely quartz-rich sandstone or limestone; exact identification requires testing

Chert / Flint

Silicon Dioxide (SiO2)

Slate

Metamorphic Pelitic Rock

Slate

Metamorphic Pelitic Rock

Chert (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

Quartzite

Metamorphic Rock consisting chiefly of Quartz (SiO2)

Quartzite

Quartzite (primarily SiO2)

Quartzite

Quartzite (primarily SiO2)

Nephrite Jade

Nephrite

Chert Nodule

Microcrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Blue gemstone cross pendant

Likely faceted blue topaz (Al₂SiO₄(F,OH)₂); identification is uncertain from the image

Sandstone (likely Graywacke or Arkose variant)

Clastic Sedimentary Rock (SiO2 based)

Sandstone (lithic wake or graywacke)

Clastic sedimentary rock (primarily quartz and lithic fragments)

Blue chalcedony cabochon (likely)

Chalcedony, microcrystalline SiO₂; possibly blue agate or common opal, which cannot be distinguished confidently from the image

Chert

Silicon dioxide (SiO2)

Weathered iron-rich limestone or altered volcanic rock

Probable limonite/goethite-bearing calcite rock; exact identification requires testing

Quartz (Chert/Chalcedony variety)

Silicon Dioxide (SiO2)

Goldstone (blue/black aventurine glass)

Man-made aventurine glass; silica glass containing metallic copper or other glittering inclusions

Rounded sandstone pebble

Quartz-rich sandstone; commonly arkose or lithic sandstone

Chert (Banded)

Cryptocrystalline Silica (SiO2)

Milky quartz / quartz-rich vein rock

Quartz, silicon dioxide (SiO₂), likely massive quartz with minor iron-staining or feldspar

Milky quartz in weathered host rock

Quartz, silicon dioxide (SiO₂), likely with iron-stained feldspar or altered matrix

Milky quartz

Quartz (silicon dioxide, SiO₂)

Pumice

Pumice (Volcanic Rock / Glass Froth)

Limestone

Calcium Carbonate (CaCO3)

Small weathered rock fragment

Indeterminate; possibly limestone or altered volcanic rock

Sandstone / Weathered Chert

Silicon Dioxide (SiO2) / Quartz-rich Clastic Rock

Weathered greenstone

Metabasalt (greenstone), likely chlorite–actinolite–epidote rock

Polished blue-green glassy slag or coated mineral fragment

Most likely man-made colored glass/slag; exact composition cannot be determined visually

Milky quartz

Quartz (silicon dioxide, SiO₂)