Red cabochon gemstone, likely carnelian or dyed chalcedony
Chalcedony (microcrystalline quartz), SiO₂; exact identification requires testing
Category
Browse organic (non geological) specimens identified by the Rock Identifier community.
Red cabochon gemstone, likely carnelian or dyed chalcedony
Chalcedony (microcrystalline quartz), SiO₂; exact identification requires testing
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified wood (primarily Quartz, SiO2)
Fossilized Bone
Vertebrate Fossil Fragment (Calcium Phosphate / Hydroxyapatite)
Black Jasper
Black Jasper (Silicate mineral - SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert / Flint
Chert (Silicon Dioxide, SiO2)
Chert (Jasper/Quartzite Pebble)
Silicon Dioxide (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Obsidian
Obsidian (principally SiO2 + MgO, Fe3O4)
Quartzite
Metamorphic Quartzite (SiO2)
Tumbled moss agate
Chalcedony (microcrystalline quartz, SiO₂) with moss-like inclusions
Snowflake Obsidian
Obsidian (volcanic glass) with Cristobalite inclusions
Milky quartz (rough quartz fragment)
Quartz, silicon dioxide (SiO₂)
Petrified Wood
Silicified Wood (SiO2)
Obsidian (specifically Mahogany Obsidian)
Volcanic glass (high silica content, SiO2)
Obsidian
Obsidian (Volcanic Glass)
Limestone
Calcium Carbonate (CaCO3)
Obsidian
Volcanic Glass (Primary component: SiO2)
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
Obsidian
Volcanic Glass (SiO2, usually 70% or more)
Limestone Concretion (Botryoidal/Calcareous Nodules)
Calcium Carbonate Concretion (CaCO3)
Obsidian Arrowhead
Volcanic Glass (Primary composition: SiO2)
Jasper
Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (and/or Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (variant Flint)
Silicon Dioxide (SiO2)
Sandstone
Arenite (primarily composed of SiO2)
Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (specifically Yellow/Brown Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Pyrite-bearing Schist
Pyritic Quartz-Mica Schist with FeS2 inclusion
Chert (Jasper/Common Opal transition)
Microcrystalline Quartz (SiO2) with iron oxide inclusions
Chert (Flint variety)
Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2
Siltstone
Siltstone (primarily composed of microcrystalline Quartz and Feldspar)
Quartzite
Quartzite (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Green Calcite
Calcium Carbonate (CaCO3)
Glauconite sand
Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Coquina Limestone (Fossiliferous Limestone)
Calcareous bioclastic sedimentary rock (CaCO3)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)