Chert (Iron-stained or Dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
Chert (Iron-stained or Dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Chert (Jasper transition)
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Iron inclusions
Manganese-coated Sandstone
Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)
Chert (Black Chert / Flint)
Silicon Dioxide (SiO2)
Chert (Nodular)
Microcrystalline Silica (SiO2)
Amber
Succinite (a variety of fossilized tree resin); chemical formula appx. C10H16O
Chert
Chert (Microcrystalline Quartz, SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (with Quartz Druzy)
Microcrystalline Silica (SiO2)
Amber
Succinate (Fossilized Tree Resin)
Chert / Flint
Silicon dioxide (SiO2)
Mother of Pearl (Nacre)
Calcium Carbonate (primarily aragonite, with conchiolin)
Chert (often called Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Green Chert (Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Chert (Dark Variety / Flint)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Amber
Succinite (Organic Mineraloid)
Chert (often called Jasper in this color)
Microcrystalline quartz (SiO2)
Chert (Siliceous Mudstone variant)
Microcrystalline quartz (SiO2)
Gravel / Limestone Fragment
Calcium Carbonate (CaCO3) / Fine-grained Sedimentary Rock
Chert (Flint)
Chert (Microcrystalline or cryptocrystalline Quartz - SiO2)
Amber
Fossilized Tree Resin (Successite)
Amber
Succinite
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Petrified Bone (Fossil Bone)
Per mineralization fossil bone (varies by organism, predominantly replacement by SiO2 - Quartz/Chalcedony)
Black Onyx and Mother of Pearl
Cryptocrystalline Quartz (SiO2) and Nacre (Calcium Carbonate)
Mother of Pearl (Nacre)
Calcium Carbonate (Aragonite) with organic conchiolin
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide / Chalcedony)
Chert (Smooth River Pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Chert (SiO2)
Chert (often called Flint)
Chert (Cryptocrystalline Silica, SiO2)
Amber
Succinate (Fossilized Tree Resin)
Petrified Wood / Fossilized Bone
Silicified / Mineralized Fossil (Silica SiO2)
Chert (often called Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert
Chert (Microcrystalline Quartz, SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Jasper
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)