Diamond (Cut Gemstone)
Carbon (C)
Category
Browse synthetic polymer (synthetic material) specimens identified by the Rock Identifier community.
Diamond (Cut Gemstone)
Carbon (C)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Boulder Opal
Hydrated Silica (SiO2·nH2O)
Diamond
Diamond (pure Carbon, C)
Limonite (Ironstone)
Limonite (mixture of hydrated iron(III) oxide-hydroxides)
Petrified Wood
Silicified Wood (SiO2)
Diamond
Carbon (C)
Petrified Rugose Coral (Horn Coral)
Order Rugosa (extinct coral)
Riverstone (Siltstone/Mudstone)
Siltstone
Sandstone (with concrete/human-made layer)
Clastic Sedimentary Rock (primarily Quartz/Feldspar grains)
Tumbled green aventurine
Quartz variety, mainly SiO₂ with fuchsite or other mica inclusions
Flint
Microcrystalline quartz (SiO2)
Tumbled green aventurine (probable)
Quartz, SiO₂, with fuchsite mica inclusions
Scoria (Volcanic Rock)
Scoria (often basaltic scoria)
Coquina
Biogenic Limestone (Coquina)
Chert (with Limestone/Dolomite host)
Microcrystalline Quartz (SiO2)
Bumblebee Jasper
Calcite-bearing Volcanic Tuff containing Sulfur and Arsenic (Orpiment/Realgar)
Agate
Silicon Dioxide (Chalcedony), SiO2
Sandstone (Tumbled / Rounded)
Sedimentary Rock (Quartz arenite)
Flint
SiO2 (Cryptocrystalline Quartz)
Flint
SiO2 (Microcrystalline Quartz)
Flint (or Chert)
Microcrystalline quartz (SiO2)
Jasper
Silicon dioxide (SiO2) with impurities, microcrystalline quartz
Jasper
Microcrystalline Quartz (SiO2)
Mammoth Molar Fossil
Mammuthus primigenius (Tooth fragment)
Fossil Snail
Gastropoda (fossilized)
Fossil Snail
Gastropoda (fossilized)
Goethite / Limonite Concretion
Iron Hydroxide Oxide (FeO(OH))
Chert (Flint) Nodule
Microcrystalline Quartz (SiO2)
Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Chert (SiO2)
Sandstone
Arenite
Chert Nodules in Limestone
Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
Chert (Chalky Flint Node)
Chert (Microcrystalline Quartz, SiO2)
Chert (with Limestone matrix)
Microcrystalline Quartz (SiO2)
Limonite
Limonite (FeOO·nH2O)
Travertine (Tufa)
Travertine (Aragonite/Calcite form of Calcium Carbonate, CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Vesicular basalt (likely weathered scoria)
Basaltic volcanic rock; chiefly plagioclase, clinopyroxene, and olivine with vesicles
Amethyst cluster
Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation
Flint
Silicon dioxide (Cryptocrystalline Quartz, SiO2)