Chert (specifically Gray/Blue Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Category
Organic (Paper And Cellulose)
Browse organic (paper and cellulose) specimens identified by the Rock Identifier community.
Chert (variant Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Chert (Flint variety)
Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2
sedimentary
Glauconitic Sandstone (Greensand pebble)
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
sedimentary
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
metamorphic
Green Banded Chert (Agate/Jasper)
Silicon Dioxide (SiO2) with trace impurities of Chlorite or Glauconite
sedimentary
Limestone with Quartz/Calcite Veins
Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO₂ - Silicon Dioxide)
metamorphic
Opalite
Synthetic Opalised Glass
Mineral (Synthetic / Man-made)
Bituminous Coal
Bituminous coal (Organic Sedimentary Rock)
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Blue Agate (Tumbled and Dyed)
Silicon Dioxide (SiO2) with likely organic dyes
mineral
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
metamorphic
Amber
Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O
Organic mineraloid
Chert (Brecciated Chert)
Silicon Dioxide (SiO2)
sedimentary
Amber
Fossilized Tree Resin (C10H16O)
mineral
River Stone (likely Mudstone or Siltstone)
Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)
sedimentary
Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende, chlorite, or manganese/iron oxides
mineral
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
Mineral (Variety of Chalcedony)
Baltic Amber
Succinite (Polmerized conifer resin)
mineraloid
Moss Agate
Chalcedony (Silicon Dioxide with inclusions) - SiO2
mineral
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Sedimentary Rock
Arid Sandy Loam
Arenosols / Regosols
sedimentary
Amber
Succinite (specifically for Baltic amber); Approximate formula: C10H16O
Organic Gemstone (Mineraloid)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides
mineral
Chert (variant Flint/Jasper)
Microcrystalline Opaline Silica (SiO2)
sedimentary
Amber
Succinite (a specific common type) or Fossilized Tree Resin (C10H16O)
Mineraloid
Tree Agate (or Moss Agate)
Dendritic Agate (Silicon Dioxide - SiO2)
mineral
Shale
Shale (fine-grained clastic sedimentary rock)
Sedimentary
Chert (Jasper/Flint variety)
Microcrystalline silicon dioxide (SiO2)
sedimentary
Jasper
Agate/Jasper (Microcrystalline Quartz, SiO2)
sedimentary
Sandstone (likely Fossilized Wood or Concrete Simulacrum)
Arenite / Silicified Wood / Anthropogenic Concrete
sedimentary
Grey and White Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Banded Chert (Flint/Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood (Silicified Wood)
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2 - Quartz/Chalcendony replacing organic matter)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2)
metamorphic
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Brecciated or Veined)
Silicon Dioxide (SiO2)
sedimentary