Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral, often found as detrital grains in sedimentary rocks
Category
Man Made Glass
Browse man made glass specimens identified by the Rock Identifier community.
Sandstone
Sandstone (lithified arenite/wacke)
Sedimentary Rock
Chert Pebble (Jasperoid/Flint)
Silicon Dioxide (SiO2) - cryptocrystalline quartz
Sedimentary
Yellow Quartzite Pebble
Quartzite (SiO2)
metamorphic
Sandstone (likely Fossilized Wood or Concrete Simulacrum)
Arenite / Silicified Wood / Anthropogenic Concrete
sedimentary
Chert (Flint)
Chert (microcrystalline quartz)
sedimentary
Chert (or Flint)
Silicon dioxide (SiO2)
sedimentary
Quartzite River Rock
Quartzite (primarily SiO2)
metamorphic
Quartz (possibly milky quartz)
Quartz (Silica; SiO₂)
Mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2)
sedimentary
Native Silver
Silver (Ag)
mineral
Chert (Chert Nodule)
Silicon Dioxide (SiO₂)
sedimentary
Mother of Pearl (Nacre)
Calcium Carbonate (primarily aragonite, with conchiolin)
Organic Gemstone/Biomineral
Chert (variant Flint/Jasper)
Microcrystalline Opaline Silica (SiO2)
sedimentary
Quartzite
Quartzite (primarily SiO2)
metamorphic
Snowflake Obsidian
Volcanic glass with Spherulite inclusions (SiO2)
igneous
Mixed Gemstone Beaded Jewelry
Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)
Mineral
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
igneous
Banded Gneiss
Gneiss (pronounced 'nice')
metamorphic
Chert (Gravel)
Silicon Dioxide (SiO2)
sedimentary
Chert (Gravel)
Chert (Cryptocrystalline silicon dioxide, SiO2)
sedimentary
Seraphinite
Clinochlore (Mg,Fe)5Al(AlSi3O10)(OH)8 - specific variety for Seraphinite due to its fibrous inclusions and chatoyancy.
Mineral
Dyed Quartz (often sold as 'Blue Quartz' or 'Blue Agate')
Silicon Dioxide (SiO2) with artificial pigment
mineral
Moonstone (specifically White Moonstone or Girasol Quartz)
Potassium aluminum silicate (KAlSi3O8)
mineral
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions (SiO2)
igneous
Chert (Arrowhead/Tool Grade)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Gravel Bit)
Microcrystalline silica (SiO2)
sedimentary
Grey Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Metamorphic Rock
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
Amber (and Citrine Quartz)
Succinite (Amber) and Silicon Dioxide (SiO2)
Organic Mineraloid and Mineral
Red Coral (Precious Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
sedimentary
Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Mineral
Stainless Steel Spoon
Iron-Chromium Alloy (Fe + Cr + Ni)
mineral-based human-made alloy
Flesh-colored Quartzite
Quartzite (SiO2)
metamorphic
Porphyritic Basalt or Diabase with Plagioclase Phenocrysts
Porphyritic Basalt or Diabase; Mineral: Plagioclase Feldspar
Igneous
Slag
Ferrous slag (by-product of iron smelting)
Mineraloid / Anthropogenic
Snowflake Obsidian
Vitreous Volcanic Glass (Siliceous Obsidian with Cristobalite inclusions)
igneous
Turquoise
Turquoise (Hydrated copper aluminum phosphate, CuAl6(PO4)4(OH)8·4H2O)
Mineral
Citrine Quartz
Silicon Dioxide (SiO2) with ferric iron impurities
mineral