Man Made Byproduct (Often Mistaken For Obsidian Or Emerald)

Sandstone with Liesegang Rings

Quartzose Sandstone with Iron Oxide Precipitation

Diamond (as set in a metal alloy ring)

Diamond (Pure Carbon, C)

Green glassy slag or manufactured glass bead

Noncrystalline silicate glass; likely industrial glass/slag, not a true mineral

Emerald crystal in host rock

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Pyrite (on Quartz matrix)

Iron Disulfide (FeS2)

Black Obsidian

Volcanic Glass (SiO2 + impurities)

Raw Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Obsidian

Volcanic glass

Obsidian

Volcanic Glass (High silica amorphous rock)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Likely obsidian (possibly tektite or slag glass)

Volcanic glass; primarily SiO₂, noncrystalline

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Green glass-like cabochon, likely synthetic glass or resin

Unidentified green transparent material; possibly molded glass, synthetic spinel, or resin

Obsidian

Amorphous volcanic glass (primarily SiO2)

Obsidian

Volcanic Glass (Mainly SiO2)

Peridot

Olivine ((Mg, Fe)2SiO4)

Black Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Obsidian

Volcanic Glass (SiO2 + impurities)

Queen Conch Shell (Biogenic Calcium Carbonate)

Aliger gigas (synonym Strombus gigas); Composition: Aragonite (CaCO3)

Quartz Vein in Host Rock (Likely Slate or Shale)

Hydrothermal Quartz (SiO2) in Pelitic host rock

Raw Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium)

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Diamond (or Simulant)

Carbon (C)

Red Sandstone

Arenite (with Iron Oxide / Hematite staining)

Obsidian

Volcanic glass (SiO2-rich)

Arsenopyrite with Schist Matrix

Arsenopyrite (FeAsS)

Ferruginous Sandstone (Ironstone)

Clastic Sedimentary Rock (composed of SiO2 with Fe2O3/FeO(OH) cement)

Chrysoprase

Chrysoprase (a variety of Chalcedony, SiO₂)

Granite

Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Obsidian

Obsidian (Volcanic Glass)

Asphalt (Road Aggregate)

Bituminous conglomerate

Peridot (Olivine)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Diamond (in jewelry setting)

Adamantine Carbon (C)

Obsidian

Obsidian (Volcanic Glass)

Obsidian

Obsidian (Volcanic Glass)

Dendritic Quartz

Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions

Asphalt Concrete

Bituminous conglomerate

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Fuchsite

Cr-bearing Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Obsidian

Obsidian (Volcanic Glass)

Beryl (likely Aquamarine or Heliodor variant)

Beryllium aluminum cyclosilicate (Be3Al2Si6O18)