Man Made Byproduct (Non Geological)

Breccia

Breccia

Loose faceted colorless gemstones, likely quartz or glass-like mineral chips

Most consistent with quartz (SiO₂), though the photograph cannot exclude synthetic cubic zirconia or glass

Granite

Granite (Felsic Plutonic Rock)

Polished greenstone pebble

Likely nephrite jade (tremolite–actinolite), though serpentine or greenstone is possible from appearance alone

Sandstone (likely Quartzose Sandstone)

Arenite

Sandstone

Arenite

Faceted purple-blue beads, likely synthetic glass or treated gemstone

Indeterminate; possible synthetic corundum, synthetic spinel, or dyed quartz (SiO₂)

Blue-green gemstone ring, likely treated turquoise or synthetic/treated beryl

Indeterminate from image; possibilities include turquoise (CuAl6(PO4)4(OH)8·4H2O), apatite, or treated beryl

Petrified Wood

Silicified Wood (SiO2)

Sandstone

Arenite

Chert (Flint)

Microcrystalline Quartz (SiO2)

Ornamental ring with likely blue sapphire and diamonds

Blue corundum (sapphire), Al₂O₃; surrounding stones appear diamond, C, set in gold-colored metal

Quartzite

Metamorphosed Quartz Sandstone

Granite

Phaneritic Igneous Rock (composed mostly of Quartz, Feldspar, and Mica)

Mixed stone-bead bracelet, likely agate/jasper and possibly sodalite or dyed quartz

Primarily microcrystalline quartz (SiO₂) varieties, with opaque iron-rich chalcedony/jasper and probable blue sodalite or dyed material

Sandstone

Arenite (variable SiO2 composition)

Weathered ironstone concretion (probable limonite/goethite nodule)

Limonite-goethite-rich iron-oxide concretion; chiefly FeO(OH)·nH₂O

Bismuth crystal

Bismuth (Bi), synthetic laboratory-grown crystal

Pearls (likely freshwater cultured pearls)

Pearl: nacre, primarily aragonite (CaCO₃) with conchiolin

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Polished black stone pendant

Likely black obsidian or black tourmaline; exact identification is uncertain from the photograph

Tumbled chalcedony (likely milky quartz)

Microcrystalline quartz, SiO₂; possibly pale agate or quartzite

Flint or chert, possibly a knapped stone tool

Microcrystalline quartz (SiO₂), commonly chalcedony with possible carbonaceous impurities

N/A - Image does not contain a rock or mineral

Anthropogenic textile material

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

Industrial vitreous slag; primarily amorphous silicate glass, composition variable

Tumbled orbicular granite

Granite, predominantly potassium feldspar, plagioclase, quartz, and biotite/hornblende

Likely flint pebble (possibly a worked flint fragment)

Microcrystalline quartz (chalcedony), SiO₂; commonly called flint

Coquina

Bioclastic Limestone

Amber-set ring

Amber (fossilized plant resin; organic mineraloid), set in a metal ring

Likely tumbled iron-stained quartz or chalcedony

Quartz/chalcedony (SiO₂), possibly limonite-coated

Granite

Granite (Felsic Plutonic Rock)

Sandstone pebble

Sandstone (arenite / quartzarenite)

Crinoid Columnal Fossil in Chert

Crinoidea stemming section in Microcrystalline Quartz (SiO2)

Goldstone (likely blue-free synthetic goldstone pendant)

Synthetic aventurine glass; silica glass with dispersed metallic copper crystals

Limestone

Calcium Carbonate (CaCO3)

Quartz (Microcrystalline/Chert)

Silicon Dioxide (SiO2)

Ironstone concretion (possible limonite/goethite-rich piece)

Iron-oxide-rich ironstone; commonly composed of goethite (FeO(OH)) and/or limonite

Zebra Rock (Zebra Stone / Ribbon Stone)

Siltstone with Ferruginous Banding (Primarily Quartz, Kaolinite, and Hematite)

River Stone (Chert/Basalt mix)

Microcrystalline Quartz (Chert) / Basalt

Polished blue stone, likely sodalite or dyed agate

Sodalite: Na₈(Al₆Si₆O₂₄)Cl₂; exact identification requires testing

Quartz Geode / Druzy Quartz

Silicon Dioxide (SiO2)

Grass (Organic Matter/Soil)

Poaceae (family of monocotyledonous flowering plants)