Green sea glass or tumbled green quartz (uncertain)
Likely quartz (SiO₂) if natural; alternatively man-made soda-lime glass
Category
Browse sedimentary (man made composite) specimens identified by the Rock Identifier community.
Green sea glass or tumbled green quartz (uncertain)
Likely quartz (SiO₂) if natural; alternatively man-made soda-lime glass
Botryoidal chalcedony (likely agate/jasper variety)
Microcrystalline quartz, SiO₂
Polished silver sheen obsidian heart
Obsidian (volcanic glass), primarily rhyolitic silica-rich glass
Green Aventurine
Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)
Slag
Ferrous Slag (Amorphous calcium-magnesium-aluminum silicates)
Man-made Jewelry (Metal and Glass/Plastic)
Synthetic Alloy and Amorphous Solid (SiO2/Polymer)
Opalite
Synthetic Opalised Glass
Carborundum (Silicon Carbide)
Silicon Carbide (SiC)
Red-orange cabochon, likely carnelian or glass imitation
Carnelian: chalcedony (microcrystalline SiO₂), commonly iron-colored
Polished black pebble, possibly obsidian
Volcanic glass (obsidian), likely; identification is tentative from the image
Tumbled milky quartz
Quartz (silicon dioxide, SiO₂)
Titanium Amethyst Geode
Silicon Dioxide (SiO2) with Titanium/Metal Vapor Deposition Layer
Green Glass (often marketed as 'Obsidian' or 'Green Quartz')
Amorphous Silica (SiO2) with copper or chromium additives
Engineered Quartz Stone
Agglomerated Quartz (SiO2 + Polymer Resin)
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)
Green sea glass (likely bottle glass)
Man-made soda–lime silicate glass; not a natural mineral
Sea Glass
Amorphous silicon dioxide (Man-made glass weathered by nature)
Blue glassy tumbled stone, likely blue chalcedony or slag glass
Chalcedony (microcrystalline SiO₂), possibly man-made blue glass
Green sea glass (likely bottle glass)
Man-made soda-lime silicate glass; not a natural mineral
Sea Glass
Amorphous Silicon Dioxide (Man-made glass weathered by nature)
Milky quartz (rough fragment)
Quartz, silicon dioxide (SiO₂)
Rock crystal (clear quartz), possibly cloudy quartz
Quartz, silicon dioxide (SiO₂)
Goldstone (Red)
Aventurine Glass (SiO2 + Cu)
Ferro-slag (Leland Blue/Slag Glass)
Anthropogenic Vitreous Silica (Industrial Slag)
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)
Graphite
Graphite (Native Carbon, C)
Jasper and Chalcedony Nodule
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Blue chalcedony (likely dyed or treated)
Microcrystalline quartz, SiO₂ (chalcedony)
Blue Obsidian (Cullet Glass)
Silicon Dioxide (Amorphous Glass)
Opalite
Synthetic glass (SiO2 + metal additions)
Tumbled milky chalcedony (likely common opalite-like quartz)
Chalcedony, microcrystalline SiO₂; possibly pale common opal, hydrated SiO₂·nH₂O
Engineered Quartz
Engineered Stone (primarily SiO2)
Raw quartz crystal
Quartz (silicon dioxide, SiO₂), likely milky or included quartz
Carborundum
Silicon Carbide (SiC)
Opalite
Synthetic Opalised Glass