Snowflake Obsidian
Volcanic glass containing Spherulitic Cristobalite (SiO2)
igneous
Category
Man Made Material (Anthropogenic 'Mineraloid')
Browse man made material (anthropogenic 'mineraloid') specimens identified by the Rock Identifier community.
Learn about Man Made Material (Anthropogenic 'Mineraloid') in the encyclopedia
View all →
Ruby in Matrix
Corundum (Al2O3)
mineral
Coquina
Bioclastic Limestone
sedimentary
Slate
Metamorphic Pelitic Rock
metamorphic
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
sedimentary
Chert or Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Exposed aggregate concrete (stone-chip surface)
Portland-cement concrete containing natural aggregate; not a natural rock
sedimentary
Amber
Succinite (Resinite)
mineraloid
Polished mahogany obsidian (probable)
Volcanic glass; chiefly rhyolitic silica-rich glass (SiO₂), compositionally near rhyolite
igneous
Limpets Shell / Fossil Specimen
Patellogastropoda (Class)
fossil
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (specifically Tan/Gray Chert)
Microcrystalline quartz (SiO2)
sedimentary
Chert (varietal: Flint/Jasper)
Silicon Dioxide (SiO2)
sedimentary
Amber
Succinite
mineraloid
Hematite Beads
Hematite (Fe2O3)
Mineral
Pink Granite
Phaneritic Felsic Igneous Rock (Granite)
igneous
Mahogany Obsidian
Obsidian (Volcanic Glass with Hematite/Magnetite inclusions), SiO2
igneous
Tektite
Tektite (high-silica natural glass)
Mineraloid
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
mineral
Tumbled chalcedony (likely moss or dendritic agate)
Microcrystalline quartz, SiO₂, with iron-oxide inclusions
mineral
Diamond
Carbon (C)
gemstone
Greenstone
Metabasalt / Metavolcanic rock
metamorphic
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert
Chert (SiO2)
sedimentary
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Nephrite Jade
Nephrite
Mineral/Rock
Quartzite Arrowhead (Archaeological Lithic)
Recrystallized Quartz (SiO2)
metamorphic
Red Slag Glass (Cullet)
Amorphous Silicon Dioxide (SiO2) with metallic dopants
Antropogenic (Man-made material)
Amber
Succinates (Organic compound: C10H16O)
mineraloid
Slate
Metamorphic Pelitic Rock
metamorphic
Slate
Metamorphic Pelitic Rock
metamorphic
Chert / Flint
Silicon Dioxide (SiO2)
sedimentary
Chert (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
sedimentary
Sea Glass
Amorphous Silica (Glass) SiO2
Mineraloid (Man-made origin)
Cullet Glass (Strawberry Glass)
Amorphous Silicon Dioxide (SiO2) with metallic dopants
Mineraloid (Synthetic/Man-made)
Weathered iron-rich rock, possibly jasper or ironstone
Likely limonite/goethite-bearing siliceous rock; exact identification requires hardness and streak tests
mineral
Polished black obsidian pyramid/block
Obsidian — natural volcanic glass, chiefly rhyolitic silica (approximately 70–75% SiO₂)
igneous
Jasper / Chert (Red)
Cryptocrystalline quartz (SiO2)
Sedimentary / Mineral
Blue chalcedony cabochon (probable)
Chalcedony, a cryptocrystalline variety of quartz; silicon dioxide, SiO₂
gemstone
Diamond
Native Carbon (C)
mineral
Man-made Dyed Aura Quartz
Silicon Dioxide (SiO2) with metallic coating/dye
mineral