Anthropogenic Specimen (Man Made)

Red jasper (likely)

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored by iron oxides

Chalcedony (Common Opal or Agate variant)

Silicon dioxide (SiO2) with trace hydration

Corundum (Sapphire variant)

Aluminium oxide (Al2O3)

Unidentified polished dark gemstone cabochon

Possibly hematite, obsidian, jet, or dark agate; image insufficient for a definitive identification

Chert (Flint Arrowhead)

Silicon Dioxide (SiO2)

Tourmalinated quartz point

Quartz (SiO₂) with black tourmaline (schorl, NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄) inclusions

Tumbled chalcedony or quartz pebble

Microcrystalline quartz (SiO₂), likely orange chalcedony/carnelian

Chert / Green Jasper

Silicon Dioxide (SiO2)

Chert (with Limestone matrix)

Silicon dioxide (SiO2)

Tumbled green glassy mineral, possibly aventurine or fluorite

Uncertain; likely quartz variety (aventurine quartz, SiO₂) or green fluorite (CaF₂)

Swirled Agate Bead

Silicon Dioxide (SiO2)

Diorite

Diorite (Intermediate intrusive igneous rock)

Chert (with Desert Varnish/Iron Stain)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Goldstone (likely blue-free synthetic goldstone pendant)

Synthetic aventurine glass; silica glass with dispersed metallic copper crystals

Tumbled brown chalcedony or jasper

Microcrystalline quartz, SiO₂; possibly iron-bearing jasper

Chert / Jasper

Silicon Dioxide (SiO₂)

Polished yellow calcite

Calcite (calcium carbonate, CaCO₃)

Fossilized echinoid (sea urchin), likely a flint/chalk-associated test

Echinoid fossil; likely a regular echinoid such as Echinocidaris or related taxon, composed mainly of recrystallized calcite (CaCO₃)

Conglomeratic concrete or asphalt aggregate surface with dark bituminous chunks

Polymictic gravel aggregate; dark pieces likely bitumen/asphalt, not a natural rock

Pumice or vesicular volcanic tuff

Pumice: highly vesicular volcanic glass, chiefly rhyolitic to dacitic; possible tuff: lithified ash and pumice fragments

Red coral (likely precious coral)

Corallium sp.; calcium-carbonate skeleton, primarily calcite

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Diamond (in a gold ring)

Diamond (pure carbon, C)

Small metallic-looking mineral/rock fragment

Indeterminate from image; possibly galena, hematite, or metallic slag

Granite

Phaneritic Felsic Igneous Rock

Amethyst

Amethyst (Silicon Dioxide - SiO2 with Iron impurities)

Chert Nodule (Flint)

Chert (Silicon Dioxide, SiO2)

Jasper

Silicon dioxide (SiO2) with impurities

Chert

Microcrystalline Quartz (SiO2)

Brecciated Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Tumbled quartz-rich pebble

Microcrystalline quartz (SiO₂), possibly milky quartz or quartzite

Limestone Pebble

Sedimentary Calcium Carbonate (CaCO3)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Paving-concrete aggregate with a rounded stone

Polymictic gravel aggregate; the central clast appears to be weathered sandstone or volcanic rock

Decorative gemstone-chip jewelry (likely turquoise, coral, and assorted beads)

Predominantly turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; other pieces appear to be dyed coral or red stone, and possibly shell/metal components

Mother of Pearl (Nacre) / Shell Fragment

Biogenic Calcium Carbonate (Aragonite and Conchiolin)

Tumbled chalcedony or quartz pebble

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

Sandstone (likely Quartzose)

Clastic sedimentary rock (SiO2 primary)

Goldstone

N/A (Synthetic Glass with Copper Inclusions)

Banded calcite (likely polished limestone/marble fragment)

Calcite, CaCO₃; probable banded calcitic marble

Pink Granite (Alkali-feldspar Granite)

Felsic intrusive igneous rock (composition: KAlSi3O8, SiO2, NaAlSi3O8)