Red Slag Glass
Amorphous Silica (Industrial byproduct with metallic oxide dopants)
Category
Browse man made composite (lithified equivalent of sedimentary) specimens identified by the Rock Identifier community.
Red Slag Glass
Amorphous Silica (Industrial byproduct with metallic oxide dopants)
Botryoidal chalcedony (likely agate/jasper variety)
Microcrystalline quartz, SiO₂
Polished silver sheen obsidian heart
Obsidian (volcanic glass), primarily rhyolitic silica-rich glass
Red goldstone beads
Goldstone (man-made copper-bearing glass; not a natural mineral)
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)
Metal Alloy (Likely Pewter or Sterling Silver)
Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).
Conglomerate
Conglomerate (clastic sedimentary rock)
Likely blue-green glassy slag or a weathered mineral fragment
Unidentified; the image does not show diagnostic features sufficient for a mineral identification
Red-orange cabochon, likely carnelian or glass imitation
Carnelian: chalcedony (microcrystalline SiO₂), commonly iron-colored
Opalite
Synthetic Opalised Glass
Carborundum (Silicon Carbide)
Silicon Carbide (SiC)
Polished black pebble, possibly obsidian
Volcanic glass (obsidian), likely; identification is tentative from the image
Green Aventurine
Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)
Slag
Ferrous Slag (Amorphous calcium-magnesium-aluminum silicates)
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
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)
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)
Green sea glass (likely)
Man-made glass, likely soda-lime silicate glass; not a natural mineral or rock
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)
Sedimentary Rock
Sedimentary rock (lithified sediment)
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)