Anthropogenic Material (Man Made Sedimentary Mimic)

Sandstone (Ferruginous)

Arenite (SiO2 with Fe2O3 inclusions)

Fossil Coral

Scleractinia (Stony Coral) fossil

Blue glass-like tumbled specimen

Most likely cobalt-blue slag glass or manufactured glass; not confidently identifiable as a natural mineral from the image

Quartz

Silicon dioxide (SiO₂)

Fulgarite

Fulgurite (Lechatelierite / Vitrified Sand)

Engineered Quartz (Quartzite look-alike)

Silicon Dioxide (SiO2) composite

Sand Tiger Shark Tooth (Fossil)

Carcharias taurus (fossilized dentin/enameloid)

Tumbled greenstone (likely serpentinite or green jasper)

Serpentinite, commonly dominated by serpentine-group minerals (Mg₃Si₂O₅(OH)₄); exact identification requires testing

Sandstone (likely Quartzose)

Clastic sedimentary rock (SiO2 primary)

Diamond

Carbon (C)

Likely iron-rich rock or weathered metallic mineral fragment

Uncertain; possibly limonite/goethite or iron-bearing slag

Polished blue-green glassy slag or coated mineral fragment

Most likely man-made colored glass/slag; exact composition cannot be determined visually

Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)

Chalcedony (SiO₂)

Chert

Microcrystalline Quartz (SiO2)

Diamond

Carbon (C)

Brecciated jasper (likely red-and-cream jasper)

Jasper, an opaque microcrystalline variety of quartz; primarily cryptocrystalline SiO₂ with iron-oxide staining and possible chalcedony/quartz veining

Zebra Jasper

Silicon Dioxide (SiO2) - Macro-crystalline Quartz/Chert with impurities

Sandstone (Pebble)

Sandstone (SiO2 with matrix/cement)

Sandstone

Arenite (SiO2 based typically)

Quartzite

Metamorphic Quartzite (SiO2)

Goldstone

N/A (Synthetic Glass with Copper Inclusions)

Tree Agate

Chalcedony (SiO2)

Marble

Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.

Unakite

Altered Granite (Epidotized Granite)

Tumbled purple quartz, likely amethyst or lavender quartz

Quartz (SiO₂), probably iron-colored amethyst; exact variety uncertain from the image

Flint

SiO2 (Cryptocrystalline Quartz)

Diamond (in jewelry setting)

Adamantine Carbon (C)

Blue Slag Glass

Amorphous Silica (Byproduct of smelting)

Chert / Flint

Chert (varieties include Flint)

Tektite

Impactite (Natural Silicate Glass)

Slate

Metamorphic pelitic rock

Sandstone

Clastic Sedimentary Rock

Gypsum (Satin Spar / Alabaster variety)

Calcium Sulfate Dihydrate (CaSO4·2H2O)

Sandstone

Arenite (composed primarily of Quartz: SiO2)

Green Aventurine

Quartz (SiO2) with Fuchsite inclusions

Bog Iron / Limonite Concretion

Goethite/Limonite mixture (FeO(OH)·nH2O)

Diamond (as set in a metal alloy ring)

Diamond (Pure Carbon, C)

Fossil Sea Urchin (Echinoid)

Echinoidea fossil (often replaced by silica or calcite)

Blue opalite (often sold as synthetic opal)

Opalite glass; amorphous hydrated silica if natural opal (SiO₂·nH₂O)

Malaysian 50 Sen Coin

Coinage (specific alloy unknown without metallurgical analysis, but typically brass or bronze for this denomination and era)

Sandstone (Pebble)

Arenite

Blue-beaded gemstone jewelry, likely lapis lazuli or dyed blue agate

Uncertain from the image; possible lazurite-bearing lapis lazuli (Na₃Ca(Si₃Al₃)O₁₂S) or blue chalcedony (SiO₂)