Man Made Rock Like Material

Coal (Anthracite / Bituminous)

Organic Sedimentary Rock (Carbon-based)

Diamond

Carbon (C)

Sunstone (Aventurine Feldspar)

(Ca,Na)((Al,Si)2Si2O8) with inclusions of Cu or Fe2O3

Polished dendritic agate cabochon (likely agate or jasper)

Microcrystalline quartz, SiO₂, commonly chalcedony with iron-oxide inclusions

Chert (often called Flint or Jasper if reddish)

Microcrystalline Quartz (SiO2)

Asphalt (Bituminous Concrete)

Bituminous mix / Anthropogenic conglomerate

Chert (Green Chert or Jasper)

Microcrystalline Quartz (SiO2)

Coquina Limestone

Coquina (Biogenic Limestone)

Chert (Flint)

Microcrystalline Silica (SiO2)

Sandstone

Arenite

Tumbled brown chalcedony or agate

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

White Marble

Recrystallized Calcite (CaCO3)

Flint (chert)

Microcrystalline quartz (SiO₂), commonly called chert or flint

Granite

Granite (felsic intrusive igneous rock)

Chert

Microcrystalline Silicon Dioxide (SiO2)

Iron-stained quartz-rich rock, possibly jasper or chert

Microcrystalline quartz (SiO₂) with iron oxides/hydroxides

Chert Arrowhead (Lithic Tool)

Microcrystalline quartz (SiO2) - Archeological lithic artifact

Unakite

Altered Granite (Epidotized Granite)

Granite

Phaneritic Plutonic Felsic Rock

Sandstone

Arenite (composed primarily of Quartz: SiO2)

Chert / Flint

Silicon Dioxide (SiO2)

Quartz Sandstone Pebble

Sandstone (SiO2 dominated)

Tumbled epidote-bearing rock (likely epidote–quartz–feldspar aggregate)

Epidote-rich metamorphic rock; minerals likely epidote (Ca₂(Al,Fe)₃Si₃O₁₂(OH), quartz, feldspar, and dark amphibole/biotite)

Red Sandstone

Arenite (Ferruginous Sandstone)

Note: Item is a Synthetic/Man-made Object

Titanium-coated Stainless Steel (Fe-Cr-Ni-Ti)

Green glassy mineral specimen, likely rough emerald or green fluorite

Tentatively beryl (Be₃Al₂Si₆O₁₈), emerald variety; synthetic/man-made glass cannot be excluded from the photograph

Blue Sapphire (Synthetic or Man-made Glass Imitation)

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

Chert / Flint

Silicon Dioxide (SiO2)

Granodiorite with Quartz Veining

Granodiorite (containing Plagioclase Feldspar, Quartz, and Biotite/Hornblende) with Quartz (SiO2) veins

Yooperlite (Syenite clast containing fluorescent Sodalite)

Sodalite-bearing Syenite

Granite

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

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (70–75% SiO2)

Granite

Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).

Petrified Wood

Silicified Wood (SiO2)

Fossilized Bored Limestone

Limestone with Ichnofossils (Gastrochaenolites or Entobia)

Likely weathered iron-rich rock or slag fragment

Uncertain; possibly limonite/goethite-rich material (FeO(OH)·nH₂O)

Likely clear quartz crystal (possibly cut/polished quartz or glass imitation)

Quartz, silicon dioxide (SiO₂)

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Vesicular basalt (likely scoria)

Basaltic scoria; predominantly plagioclase, pyroxene, and olivine in a mafic volcanic glass/microcrystalline matrix

Coquina

Coquina (Biogenic Limestone / CaCO3)

Chert (often called Flint or Jasper)

Microcrystalline Quartz (SiO2)

Amber cabochon pendant

Amber (fossilized plant resin), chiefly polymerized diterpenoid resin