Quartzite Pebble (River Rock)
Quartzite (SiO2)
metamorphic
Category
Man Made Silicate (Anthropogenic Glass)
Browse man made silicate (anthropogenic glass) specimens identified by the Rock Identifier community.
Chert (Flint Pebbles)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Rose Quartz
Rose Quartz (SiO2)
Mineral
Obsidian
Obsidian (Volcanic Glass)
igneous
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
igneous
Chlorite (Small Flakes/Sand)
Chlorite Group (Magnesium Iron Aluminum Silicate Hydroxide - (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)
mineral
Obsidian
Volcanic glass (SiO2 + impurities)
igneous
Red Jasper
Silicon dioxide (SiO2) with hematite impurities
sedimentary
Red Garnet
Pyrope or Almandine (Silicate group, X3Y2(SiO4)3)
Mineral
Yellow Jasper
Jasper (Silica-rich Microcrystalline Quartz, SiO2 with Iron impurities)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Amber (and Citrine Quartz)
Succinite (Amber) and Silicon Dioxide (SiO2)
Organic Mineraloid and Mineral
Red Coral (Precious Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
sedimentary
Serpentinite
Serpentinite (composed primarily of serpentine-group minerals like antigorite, chrysotile, and lizardite; chemical formula varies but generally Mg3Si2O5(OH)4)
Metamorphic Rock
Amethyst
Amethyst (Silicon Dioxide, SiO2 + Fe4+ impurities)
mineral
Mica Schist
Mica Schist (predominantly Muscovite or Biotite sheet silicates)
metamorphic
Amazonite
Potassium Aluminum Silicate (KAlSi3O8)
mineral
Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Mineral
Vesicular Basalt
Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)
igneous
Quartzite (or Ferruginous Quartz)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
metamorphic
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Mineral
Stainless Steel Spoon
Iron-Chromium Alloy (Fe + Cr + Ni)
mineral-based human-made alloy
Red Shale
Lutite (primarily composed of Hydrous Aluminum Silicates with Hematite staining)
sedimentary
Obsidian
Obsidian (Volcanic glass), 70-75% SiO2
igneous
Fulgurite
Fulgurite (Lechatelierite-rich fused silica)
mineraloid
Milky Quartz (Water-worn Pebble)
Quartz (Silicon Dioxide, SiO2)
mineral
Jasper
Silicon dioxide / Chalcedony (SiO2)
Sedimentary
Flesh-colored Quartzite
Quartzite (SiO2)
metamorphic
Porphyritic Basalt or Diabase with Plagioclase Phenocrysts
Porphyritic Basalt or Diabase; Mineral: Plagioclase Feldspar
Igneous
Amazonite
Potassium aluminum silicate (KAlSi3O8)
mineral
Beryl (likely var. Aquamarine or Goshenite) in Matrix
Beryllium Aluminum Silicate (Be3Al2Si6O18)
mineral
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 inclusions)
sedimentary
Red Jasper
Jasper (a variety of Chalcedony, SiO₂ with iron oxide inclusions)
Mineral
Quartzite pebble
Quartzite (SiO2)
metamorphic
Sandstone
Arenite (primarily SiO2)
sedimentary
Quartzite (River Cobble)
Quartzite (mostly SiO2)
metamorphic
Yellow Jasper
Silicon Dioxide (SiO2) with impurities of Iron or Goethite
sedimentary
Serpentine (Serpentinite)
Serpentinite (complex silicate group including lizardite, chrysotile, and antigorite)
metamorphic
Blue Topaz (specifically London Blue or Swiss Blue based on color saturation)
Al2SiO4(F,OH)2 (Aluminum Silicate Fluoride Hydroxide)
mineral
Mahogany Obsidian
Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)
igneous
Sugilite
KNa2(Fe,Mn,Al)2Li3Si12O30 (Potassium Sodium Lithium Iron Manganese Aluminum Silicate)
mineral