Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Category
Organic Gemstone (Fossilized Resin)
Browse organic gemstone (fossilized resin) specimens identified by the Rock Identifier community.
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Tufa (Vesicular Limestone)
Tufa (form of Calcium Carbonate, CaCO3)
sedimentary
Sandstone (Banded)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
sedimentary
Septarian Nodule (Dragon Stone)
Septarian concretion (composition: Calcium Carbonate / Calcite, Aragonite, and Limestone/Clay)
sedimentary
Pearl
Calcium Carbonate (CaCO3) - Aragonite/Calcite
mineral
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary (fossilized)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Moss Agate
Chalcedony (Silicon Dioxide - SiO2) with inclusions
Mineral
Chert (often called Flint)
Chert (Silicon Dioxide, SiO2)
sedimentary
Sphalerite with Galena
Zinc Sulfide ((Zn,Fe)S) and Lead Sulfide (PbS)
mineral
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Atlantic Calico Scallop (Biogenic Aragonite/Calcite)
Argopecten gibbus (Chemical: CaCO3)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
mineral
Petrified Wood
Silicified wood (Quartz/Chalcedony)
Sedimentary
Red Chert
Microcrystalline Quartz (SiO2)
sedimentary
Jet
Lignite (Anthracite-grade compact coal)
sedimentary
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
mineral
Black Pearl (Tahitian-style Cultured Pearl)
Calcium Carbonate (Aragonite) with Conchiolin (CaCO3)
mineral
Orthoceras Fossil Limestone
Orthoceras (extinct genus of cephalopod); Limestone matrix (CaCO3)
sedimentary
Picture Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Dendritic Agate (Tumbled)
Silicon Dioxide (SiO2) with inclusions
mineral
Biggs Jasper (Picture Jasper)
Silicon Dioxide (SiO2) - Opaque Silicified Volcanic Ash
sedimentary
Moss Agate / Chalcedony
Silicon Dioxide (SiO2)
mineral
Mookaite Jasper
Silicon Dioxide (SiO2) - variety of Chert/Jasper
sedimentary
Sea Shell (Fighting Conch Fragment)
Calcium Carbonate (CaCO3) - Strombus alatus fragment
sedimentary (biogenic)
Quartz (Engineered Stone Countertop)
Silicon Dioxide (SiO2) within a resin matrix
igneous
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
mineraloid
Chert (White Flint)
Silicon Dioxide (SiO2)
sedimentary
Pink Orthoclase Feldspar with Dendrites
Orthoclase (KAlSi3O8) with Manganese Oxide dendrites
mineral
Dendritic Opal
Opalized Chalcedony with Manganese Inclusions (SiO2 · nH2O)
mineral
Picture Jasper
Silicon Dioxide (SiO2) with mineral inclusions
sedimentary
Petrified Wood (Jet or Coalified Wood appearance)
Silicified wood (principally SiO2) or Carbonized Wood
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Chert (Iron-stained or Dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Terrazzo (Synthetic Composite Rock)
Cementitious or Epoxy Resin-bound Aggregates
Man-made metamorphic-style composite
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3
mineral
Pearl
Aragonite / Calcium Carbonate (CaCO3)
mineral