Man Made Material (Constructed)

Diamond

Carbon (C)

Sandstone (Quartz Arenite)

Sandstone (dominated by SiO2 quartz grains)

Unakite

Altered Granite (Epidotized Granite)

Nacre (Mother of Pearl)

Nacre (Biogenic Aragonite/Calcite composite, CaCO3)

Likely smoky quartz pendant

Smoky quartz, silicon dioxide (SiO₂), quartz variety colored by irradiation-related defects

Likely iron-rich rock or weathered metallic mineral fragment

Uncertain; possibly limonite/goethite or iron-bearing slag

Tumbled brown chalcedony or agate

Microcrystalline quartz (SiO₂), likely chalcedony; possibly iron-stained jasper or agate

Botryoidal chalcedony with iron-oxide staining

Microcrystalline quartz (SiO₂), likely iron-oxide-bearing chalcedony

Diamond

Carbon (C)

Tumbled chalcedony (likely milky quartz)

Microcrystalline quartz, SiO₂; possibly pale agate or quartzite

Red glass-like crystal, likely synthetic ruby or red glass

Uncertain from image; possible corundum (ruby), Al₂O₃, or synthetic glass

Chert (often called Flint)

Chert (Cryptocrystalline Quartz, SiO2)

Fossilized gastropod (likely nerite or related sea snail)

Gastropoda; shell composed originally of aragonite/calcite, commonly replaced or infilled by calcite

Amethyst gemstone ring

Quartz, purple variety — SiO₂

Diorite (Gneissic)

Diorite

Tumbled chalcedony or quartz pebble

Microcrystalline quartz (SiO₂), likely orange chalcedony/carnelian

Flint (chert) nodule

Microcrystalline quartz (SiO₂), occurring as a flint/chert nodule in limestone

Eurasite (or Ferruginous Sandstone)

Ferruginous Sandstone (SiO2 with Fe2O3/FeOOH)

Beach Pebble (Chalcedony / Chert)

Silicon Dioxide (SiO2)

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

Industrial vitreous slag; primarily amorphous silicate glass, composition variable

Sandstone (Quartzose)

Arenite (primarily SiO2)

Quartzite

Metamorphic Quartzite (SiO2)

Granodiorite

Granodiorite

Sandstone

Arenite (variable SiO2 composition)

Flint (chert), likely a worked stone flake

Microcrystalline quartz (SiO₂); cryptocrystalline variety of quartz

Polished orbicular granite heart

Granite, commonly quartz–alkali feldspar–plagioclase–biotite granite; exact locality-dependent

Chert (Flint/Chalcedony)

Silicon Dioxide (SiO2)

Chert Arrowhead

Chert (Cryptocrystalline variety of Quartz, SiO2)

Raw Diamond

Carbon (C)

Chert (Common Opal/Jasper variety)

Cryptocrystalline Quartz (SiO2)

Chert (and/or Flint)

Microcrystalline Quartz (SiO2)

Diamond (in jewelry setting)

Carbon (C)

Tumbled chalcedony or quartz pebble

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

Polished brecciated jasper pendant

Jasper, an opaque microcrystalline variety of chalcedony (mostly SiO₂), with iron-oxide staining and likely brecciation

Sandstone

Clastic sedimentary rock (primarily SiO2)

Goldstone (Synthetic Aventurescence Glass)

Cuprous Aventurescent Glass (Silicon Dioxide with Copper inclusions)

Decorated turquoise-like bead or mineral pendant

Likely turquoise [CuAl₆(PO₄)₄(OH)₈·4H₂O], possibly dyed composite or blue-green jasper

Pink Granite

Phaneritic Felsic Igneous Rock (composed of orthoclase, quartz, and plagioclase)

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Flint)

Chert (SiO2)

Chert (Green Chert or Jasper)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)