Limestone (Travertine/Tufa variant)
Calcium Carbonate (CaCO3)
Category
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
Limestone (Travertine/Tufa variant)
Calcium Carbonate (CaCO3)
Milky Quartz Pebble with Iron Inclusions
Silicon Dioxide (SiO2)
Vesicular Basalt (or Scoria)
Extrusive Igneous Rock (Mafic)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxide
Amber
Succinite (Fossilized Tree Resin) - C10H16O
Chert (Nodule)
Silicon Dioxide (SiO2)
Dinosaur Bone (Gembone)
Agatized Dinosaur Bone (Silicified Paleo-osteoid)
Amber
Succinicum (Organic polymer, largely C10H16O)
Amethyst (Geode/Cluster)
Silicon Dioxide (SiO2) with iron impurities
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Purple Agate (Dyed Chalcedony)
SiO2 (Silicon Dioxide) with organic dyes
Amber
Succinite (Fossilized Tree Resin)
Moss Agate
Silicon dioxide (SiO2) with mineral inclusions
Petrified Wood
Silicified Wood (SiO2)
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
Basalt
Basalt
Ambergris
Ambergris (Coprolite-adjacent/Organic secretion)
Polished/tumbled calcite
Calcite (calcium carbonate, CaCO₃)
Copper Ore / Altered Granodiorite
Cupriferous rock with silicate gangue
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
Granite
Granite
Granodiorite (Weathered)
Granodiorite
Druzy Quartz on Chert/Chalcedony
Silicon Dioxide (SiO2)
Granite Pebbles
Granite (composed primarily of Quartz SiO2, Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8), and Mica)
Amber
Fossilized Tree Resin (Organic Polymer)
Granite Pebble
Granite (Plutonic Igneous Rock)
Quartz Vein in Basalt or Mafic Rock
Silicon Dioxide (SiO2) vein in volcanic/mafic matrix
Quartz-veined Basalt or Limestone Pebble
Quartz vein in host rock (Silicate mineral in carbonate or volcanic matrix)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Anthracite Coal
Anthracite
Chert (Yellow Chert/Flint)
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Amber
Succinite (fossilized resin)
Tufa (Calcareous Tufa)
Calcareous Tufa (Precipitated CaCO3)
Chrysanthemum Stone
Celestine (SrSO4) or Calcite (CaCO3) in Limestone/Porphyry matrix
Basalt
Extrusive igneous rock
Agate Geode
Silicon Dioxide (SiO2) - Chalcedony variety
Quartz Vein in Metamorphic Rock
Quartzite or Schist host with Quartz (SiO2) intrusion
Tonsil Stone (Tonsillolith)
Calcium phosphate / Calcium carbonate biomineral
Petrified Wood
Silicified Wood (Permineralized organic tissue)
Chert
Chert (Microcrystalline Quartz, SiO2)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)