Anthropogenic Material (Man Made Rock)

White pebbles (rock material not identifiable from the image)

Undetermined; the smooth, pale pieces could be quartz, quartzite, or another light-colored rock

Chert (specifically Tan/Gray Chert)

Microcrystalline quartz (SiO2)

Mystic Topaz

Aluminum Silicate Fluoride Hydroxide (Al2SiO4(F,OH)2) with metallic film coating

Opalite

Synthetic Glass (Hydrated Crystalline Silicon Dioxide simulation)

Orange glassy slag (industrial by-product)

Iron-rich silicate glass; composition varies, commonly Fe–Ca–Al silicate

Obsidian (Blue)

Volcanic Glass (SiO2)

Blue Cracked Quartz (Dyed Fire Crackle Quartz)

Silicon Dioxide (SiO2) with synthetic dye

Pink Quartz / Sea Glass

Silicon Dioxide (SiO2)

Conglomeratic gravel / polymictic breccia

Polymictic rudite, likely anthropogenic or beach/stream gravel; composition varies

Tumbled opalite (likely synthetic glass)

Opalite; typically man-made opalescent soda-lime glass, not a recognized mineral species

Blue goldstone

Man-made aventurine glass containing metallic copper particles; not a natural mineral

Likely polished quartz or glass-like mineral cabochon

Probably quartz (SiO₂), though the image cannot exclude man-made glass

Chert Arrowhead (Projectile Point)

Microcrystalline Quartz (SiO2)

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

Sandstone

Arenite

Beaded gemstone bracelet

Indeterminate; likely small polished mineral beads, possibly turquoise or dyed stone, with metal and glass components

Chert (Flint)

Silicon Dioxide (SiO2)

Limpets Shell / Fossil Specimen

Patellogastropoda (Class)

Opalite

Synthetic Glass (Simulated Moonstone/Opal)

Diamond (or Cubic Zirconia)

Carbon (C) or Zirconium Dioxide (ZrO2)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Likely slate

Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals and quartz

Sandstone

Arenite (with iron oxide cement)

Quartz (likely milky quartz or quartz glass-like fragment)

Quartz, silicon dioxide (SiO₂)

Chert (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

Tumbled opalite (likely man-made glass)

Opalite, a trade name for opalescent glass; not natural opal

Blue Goldstone

Aventurine Glass

Strawberry Quartz

Silicon Dioxide (SiO2) with Hematite/Goethite inclusions

Chert (Flint)

Silicon Dioxide (SiO2)

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

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

Industrial vitreous slag; primarily amorphous silicate glass, composition variable

Granite / Diorite (Granodiorite)

Granodiorite / Quartz Diorite

Black tumbled stone, possibly obsidian

Obsidian (volcanic glass; predominantly SiO₂), identification uncertain from image

Weathered concrete or cementitious slab (not natural rock)

Artificial calcium-silicate cement composite; likely Portland cement concrete

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

Opalite

Synthetic Opalized Glass

Iron Slag

Anthropogenic Vitreous Ferrous Silicate

Asphalt fragment

Bituminous concrete

Fluorite (Polished Point/Tower)

Calcium Fluoride (CaF2)

Polished jasper pebble

Jasper, an opaque microcrystalline variety of quartz (SiO₂), with possible iron-oxide and other mineral inclusions

Opalite (a synthetic glass, often confused with Opal)

Silicon dioxide glass (SiO2nH2O, for natural opal)

Sandstone

Sedimentary Rock (Quartz Sandstone)