Man Made Material, Not A Natural Rock Or Mineral Specimen

Opalite

Synthetic Opalised Glass

Sandstone Concretion

Septarian or Carbonate-cemented Sandstone Concretion

Diamond (in a jewelry setting)

Carbon (C)

Aventurine

Quartz containing inclusions of Fuchsite (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)

Boxwork or Septarian Concretion

Septarian nodule / Boxwork weathering

Quartz crystal (likely clear quartz)

Quartz, silicon dioxide (SiO₂)

Clear quartz fragment

Quartz (silicon dioxide, SiO₂)

Beaded gemstone bracelet, likely lapis lazuli and pale quartz/agate

Lapis lazuli: lazurite-rich rock, chiefly (Na,Ca)₈(AlSiO₄)₆(S,SO)₂; pale beads are uncertain

Chert (Arrowhead/Artifact Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Turquoise cabochon ring

Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Milky quartz (rough fragment)

Quartz, silicon dioxide (SiO₂)

Painted Sandstone

Sandstone (clastic sedimentary rock) with acrylic/artistic coating

Tumbled black obsidian (likely)

Volcanic glass; chiefly silica-rich rhyolitic glass (SiO₂)

Asphalt Pavement (with aggregate)

Asphalt concrete

Clear quartz crystal

Quartz (silicon dioxide, SiO₂)

Dyed Blue Agate Slice

Silicon Dioxide (SiO2)

Eroded Brick or Pumice-like Scoria

Vesicular Basalt / Scoria (Anthropogenic variant: Eroded Firebrick)

Raw quartz crystal

Quartz (silicon dioxide, SiO₂), likely milky or included quartz

Quartz-rich stone, possibly aventurine quartz or quartzite

Quartz (SiO₂), likely massive or microcrystalline; exact identification requires testing

Weathered stone nodule or concretion

Unidentified lithic concretion; composition cannot be determined from the image

Yellow cabochon gemstone, likely citrine or yellow glass imitation

Quartz (SiO₂), if natural citrine; visual evidence is insufficient to exclude man-made glass or resin

Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)

Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)

Diamond

Carbon (C)

Slag

Anthropogenic glassy silicate

Fossil or modern bivalve shell

Calcium carbonate shell, likely aragonite (CaCO₃); exact species cannot be determined from the image

Dyed Agate / Painted Stone

Silicon Dioxide (SiO2) with artificial pigment

Polished black stone, likely black obsidian

Obsidian (volcanic glass), chiefly silica-rich rhyolitic composition

Green Slag Glass

Cullet (Amorphous Silicon Dioxide with impurities)

Sandstone

Arenite (SiO2 primarily)

Polished silver sheen obsidian heart

Obsidian (volcanic glass), primarily rhyolitic silica-rich glass

Diamond

Native Carbon (C)

Hematite Beads

Hematite (Fe2O3)

Weathered iron-rich rock, possibly jasper or ironstone

Likely limonite/goethite-bearing siliceous rock; exact identification requires hardness and streak tests

Dark, weathered stone—possibly basalt or slag

Indeterminate; likely fine-grained basalt (plagioclase–pyroxene)

Sandstone

Clastic Sedimentary Rock

Sandstone (Quartzose)

Arenite (primarily SiO2)

Vesicular basalt (probable iron-rich volcanic rock)

Basalt; chiefly plagioclase, clinopyroxene, olivine, and Fe-Ti oxides

Amethyst crystal fragment

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron and irradiation

Fossilized coral with attached shell

Likely fossil coral (Scleractinia or Tabulata), with a bivalve or gastropod shell; exact identification requires microscopy

Sandstone (specifically Arkose or Quartz Arenite)

Arenite (primarily SiO2 with possible Feldspar)

Corundum (Sapphire/Ruby in Matrix)

Corundum (Al2O3)

Blue Sapphire (Synthetic or Man-made Glass Imitation)

Corundum (Al2O3) if natural; Lead-glass or Spinal if synthetic