Blue-green cabochon, likely chalcedony or treated glass imitation
Cryptocrystalline quartz (chalcedony/possibly chrysoprase); identification uncertain from image
Category
Browse anthropogenic sedimentary (man made) specimens identified by the Rock Identifier community.
Blue-green cabochon, likely chalcedony or treated glass imitation
Cryptocrystalline quartz (chalcedony/possibly chrysoprase); identification uncertain from image
Blue Obsidian
Volcanic Glass (SiO2 with inclusions)
Green glass sphere/marble
Soda-lime glass (primarily SiO2, Na2O, CaO)
Milky quartz (rough fragment)
Quartz, silicon dioxide (SiO₂)
Rock crystal (clear quartz), possibly cloudy quartz
Quartz, silicon dioxide (SiO₂)
Tumbled milky quartz
Quartz (silicon dioxide, SiO₂)
Titanium Amethyst Geode
Silicon Dioxide (SiO2) with Titanium/Metal Vapor Deposition Layer
Chert Arrowhead (Lithic Artifact)
Microcrystalline Quartz (SiO2)
Green Glass (often marketed as 'Obsidian' or 'Green Quartz')
Amorphous Silica (SiO2) with copper or chromium additives
Goldstone beads (likely brown goldstone)
Man-made copper-bearing glass; not a natural mineral. Often sold as “aventurine glass.”
Goldstone (Red)
Aventurine Glass (SiO2 + Cu)
Blue Crackle Quartz (Dyed Quarzite)
Silicon Dioxide (SiO2) with artificial dye
Dyed Blue Agate (Dragon Vein Agate)
Silicon Dioxide (SiO2) with artificial cobalt/organic dyes
Diamond
Native Carbon (C)
Dyed Aura Quartz
Silicon Dioxide (SiO2) with metallic coating
Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)
Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)
Granite with Cupules / Bedrock Mortars
Granite (felsic intrusive plutonic rock)
Green sea glass (likely)
Man-made glass, likely soda-lime silicate glass; not a natural mineral or rock
Chert (Arrowhead/Projectile Point)
Chert (Cryptocrystalline Quartz, SiO2)
Opalite
Synthetic glass (SiO2 + metal additions)
Raw quartz crystal
Quartz (silicon dioxide, SiO₂), likely milky or included quartz
Blue chalcedony (likely dyed or treated)
Microcrystalline quartz, SiO₂ (chalcedony)
Blue Obsidian (Cullet Glass)
Silicon Dioxide (Amorphous Glass)
Tumbled milky chalcedony (likely common opalite-like quartz)
Chalcedony, microcrystalline SiO₂; possibly pale common opal, hydrated SiO₂·nH₂O
Obsidian (likely black volcanic glass)
Obsidian; primarily amorphous volcanic silica glass, approximately SiO₂-rich rhyolitic composition
Carborundum
Silicon Carbide (SiC)
Opalite
Synthetic Opalised Glass
Carborundum (Silicon Carbide)
Silicon Carbide (SiC) / Moissanite (natural form)
Opalite-style pendant (likely synthetic glass, not natural opal)
Opalescent glass; commonly sold as “opalite” (not a recognized mineral species)
Cullet (Slag Glass)
Amorphous Silica (Industrial byproduct)
Chert (Arrowhead Debitage or Flake)
Microcrystalline silica (SiO2)
Agate and millefiori glass jewelry
Agate: microcrystalline quartz (SiO₂); millefiori element appears to be man-made glass
Polished obsidian
Volcanic glass; predominantly rhyolitic SiO₂
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
Chert (Arrowhead/Projectile Point)
Cryptocrystalline Quartz (SiO2)
Blue Goldstone
Synthetic Avanturine Glass (or Aventurine Glass)
Pink Cubic Zirconia (CZ)
Zirconium Dioxide (ZrO2)
Green glassy mineral fragment, possibly fluorite
Fluorite (calcium fluoride, CaF₂), tentative identification
Asphalt Chunk
Asphalt concrete
Man-made Ceramic / Clay Figurine
Aluminosilicate Ceramic (Processed Clay)
Glass / Silicon Dioxide (Man-made)
SiO2 (Amorphous Silicon Dioxide)
Man-made Blank Ammunition (Brass)
CuZn (Cartridge Brass - roughly 70% Copper, 30% Zinc)