Chert (often called Jasper in this color)
Microcrystalline quartz (SiO2)
Category
Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.
Chert (often called Jasper in this color)
Microcrystalline quartz (SiO2)
Polished moss agate
Moss agate, a variety of chalcedony (microcrystalline quartz, SiO₂)
Chert (often called Flint in dark varieties)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Nodular)
Microcrystalline Silica (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Amber
Succinite (Fossilized Resin)
Amber
Succinite / Fossilized Resin (C10H16O)
Amber
Succinite
Jasper
Jasper (Cryptocrystalline variety of Quartz, SiO2)
Shale or Slate
Shale (Sedimentary) or Slate (Metamorphic)
Amber
Succinite (Fossilized Tree Resin, C10H16O)
Limestone or Sandstone Cobble
Sedimentary rock (Calcium carbonate or Quartz based)
Chert (Gray Chalcedony)
Microcrystalline Quartz (SiO2)
Amber
Succinite (Approximate formula: C10H16O)
Moss agate bracelet
Chalcedony (microcrystalline quartz, SiO₂) with chlorite/amphibole inclusions
Amber
Succinite (fossilized resin)
Polished banded agate (likely picture jasper or petrified wood)
Microcrystalline quartz, SiO₂, with iron-oxide and clay inclusions
Chert (Green variety)
Silicon Dioxide (SiO2)
Gravel / Limestone Fragment
Calcium Carbonate (CaCO3) / Fine-grained Sedimentary Rock
Amber
Succinite
Fossiliferous Sandstone
Sedimentary rock containing invertebrate fossils
Pearl
Nacre (aragonite, CaCO₃, in a conchiolin matrix)
Pearl
Calcium Carbonate (CaCO3) + Conchiolin
Pearl
Nacre (aragonite, CaCO₃, in an organic conchiolin matrix)
Green Jasper
Microcrystalline Quartz (SiO2) with mineral inclusions
Chert (and its variety Flint)
Silicon dioxide (SiO2) / Microcrystalline quartz
Pearl
Organic gemstone (Calcium carbonate / CaCO3 + Conchiolin)
Limestone with Fossil Fragment
Sedimentary carbonate rock (CaCO3)
Blue Apatite
Calcium Phosphate (Ca5(PO4)3(F,Cl,OH))
Pearl
Calcium carbonate (CaCO3) + organic conchiolin
Shale
Laminated Fissile Pelite
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Sandstone (with Moss)
Quartz Arenite / Sandstone
Quartz pebble or seed/crumb
SiO2 (if quartz)
Pearl
Calcium carbonate (CaCO3) in the form of Aragonite or Calcite
Moss Agate
Silicon Dioxide (Chalcedony variety) with green hornblende or chlorite inclusions - SiO2
Fossil gastropod shell
Fossilized marine gastropod; exact genus/species cannot be determined from the image
Chert (Yellow/Tan)
Microcrystalline Quartz (SiO2)
Freshwater Pearl
Calcium Carbonate (CaCO3) - Aragonite/Calcite organic composite
Chert (Green and Black Jasper variant)
Cryptocrystalline Quartz (SiO2)
Green Chert
Microcrystalline Quartz (SiO2)
Quartz-veined Limestone
Sedimentary limestone with quartz/calcite veinlets