Man Made Material (Anthro Lithic Product)

Polished amethyst-bearing quartz

Quartz, SiO₂; purple coloration from irradiation and trace iron

Yellow faceted gemstone, likely citrine or synthetic glass

Citrine (quartz, SiO₂) is the leading natural possibility; visual identification is uncertain from the photograph

Likely flint (chert) fragment

Chert, microcrystalline quartz (SiO₂)

Vesicular basalt (probable scoriaceous basalt)

Basalt, composed mainly of plagioclase feldspar, pyroxene, and commonly olivine

Red Slag Glass (Cullet)

Amorphous Silicon Dioxide (SiO2) with metallic dopants

Sandstone

Sedimentary Rock (Quartz arenite / Lithic sandstone)

Jasper / Chert (Red)

Cryptocrystalline quartz (SiO2)

Weathered mineralized rock fragment

Indeterminate; likely quartz–feldspar-rich lithic material with iron-oxide staining

Chert (Flint Nobule)

Silicon Dioxide (SiO2)

Colorless faceted gemstone, likely glass or cubic zirconia

Uncertain; possible cubic zirconia (ZrO₂) or quartz (SiO₂), but the image may show a man-made simulant

Red coral (likely precious coral)

Corallium sp.; calcium-carbonate skeleton, primarily calcite

Chert (specifically Flint or Nodular Chert)

Silicon dioxide (SiO2)

Chert (Jasper/Flint var.)

Silicon Dioxide (SiO2)

Chert (often called Flint or River Stone)

Microcrystalline alpha-quartz (SiO2)

Chert (Chert / Flint Variety)

Microcrystalline / Cryptocrystalline Quartz (SiO2)

Hematite (Iron Ore Boulder)

Hematite (Fe2O3)

Rounded sandstone pebble

Quartz-rich sandstone, likely arkosic or lithic sandstone

Rounded sandstone pebble

Quartz-rich sandstone, likely arkose or lithic sandstone

Weathered sandstone pebble

Quartz-rich sandstone, likely arkosic or lithic sandstone

Small rounded pebble, likely quartz-rich river stone

Indeterminate; likely quartz/chert-bearing lithic clast

Fossilized bivalve shell fragment

Calcitic mollusk shell, commonly Bivalvia; exact genus cannot be determined from the image

Chert (Arrowhead Preform)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Jasper)

Silicon Dioxide (SiO2)

Chert Nodule (Flint)

Chert (Silicon Dioxide, SiO2)

Tumbled river pebble, likely fine-grained sandstone or mudstone

Indeterminate lithic clast; possibly quartz-rich sandstone or siltstone

Travertine

Calcium Carbonate (CaCO3)

Asphalt aggregate (crushed stone in bitumen)

Artificial composite; predominantly crushed granite, basalt, limestone, and/or recycled aggregate bound by bitumen

Diamond (as set in a gold ring)

Carbon (C)

Weathered granite or granitic gneiss fragment

Quartz–feldspar–mica aggregate; likely granite (possibly gneiss)

Unidentified brown rock fragment

Indeterminate from image; likely a weathered iron-rich lithic fragment

Rounded gray sandstone cobble

Quartz-rich sandstone (likely arkose or lithic sandstone)

Tumbled greenstone-like pebble

Likely serpentine or chlorite-rich metamorphic rock; exact identification requires testing

Dark basalt (likely porphyritic basalt)

Basalt, composed mainly of plagioclase feldspar, pyroxene, and commonly olivine

Chert (Arrowhead/Projectile Point)

Cryptocrystalline Quartz (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Sandstone (likely Arkosic or Lithic)

Clastic Sedimentary Rock (composed mostly of SiO2)

Asphalt (Bituminous Concrete)

Bituminous Concrete / Pavement

Chert (flint) fragment

Microcrystalline quartz (SiO₂), commonly called chert or flint

Small rounded pebble, likely quartz-rich sandstone or granitic fragment

Indeterminate lithic clast; possible quartz–feldspar aggregate

Tumbled quartz-rich pebble

Likely quartzite or quartz-rich sandstone; predominantly SiO₂

Rounded sandstone pebble

Quartz-rich sandstone, likely subarkose or lithic sandstone