Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Category
Mineral (Silicate Replaced Organic Material)
Browse mineral (silicate replaced organic material) specimens identified by the Rock Identifier community.
Learn about Mineral (Silicate Replaced Organic Material) in the encyclopedia
View all →
Red Jasper / Chert
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Petrified Wood
Silicified wood (Quartz, SiO2)
metamorphic
Petrified Wood
Silicified Wood (primarily SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
mineral
Tumbled jasper or chert
Microcrystalline quartz (SiO₂), commonly jasper/chalcedony
mineral
Fossil crocodilian skull and jaws
Crocodyliform fossil; exact genus and species cannot be determined from the image
fossil
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
metamorphic
Petrified Wood
Silicified Wood (primarily Quartz/SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
mineral
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Tumbled brown jasper (probable)
Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide impurities
mineral
Petrified Wood
Silicified Wood (Silicon Dioxide - SiO2)
fossil
Chert (Common Opal or Agate)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood / Red Jasper
Silicified wood (primarily Silicon Dioxide, SiO2)
sedimentary
Chert (varieties include Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
![Fossilized bone fragment (probable mammalian tooth or bone) (Mineralized bone, commonly hydroxyapatite [Ca5(PO4)3(OH)] replaced or impregnated by silica/calcite) — fossil](https://media.rock.id/fossilized-bone-fragment-probable-6435bbec-570b-407e-9c9f-870b904b8d23-thumbnail.jpg)
Fossilized bone fragment (probable mammalian tooth or bone)
Mineralized bone, commonly hydroxyapatite [Ca5(PO4)3(OH)] replaced or impregnated by silica/calcite
fossil
Shale
Shale (clay-sized silicate minerals)
sedimentary
Fossiliferous Jasper / Miriam Stone / Elephant Skin Jasper
Biogenic Chalcedony / Silicified Fossiliferous Limestone
fossil
Petrified Wood
Silicified wood (Quartz, SiO2)
fossil
Chert / Chalcedony (Agatized)
Silicon dioxide (SiO2)
sedimentary
Chert with Iron Inclusions
Microcrystalline Quartz (SiO2) with Hematite/Limonite
sedimentary
Chert (often called Flint when found in chalk)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement)
fossil
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Iron-stained)
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Petrified Wood
Silicified wood (Quartz/Chalcedony/SiO2)
sedimentary
![Possible fossilized bone fragment (Fossil bone, composition primarily carbonate-hydroxylapatite [Ca₅(PO₄)₃(OH)]) — fossil](https://media.rock.id/possible-fossilized-bone-fragment-494ea971-834f-4186-bf0b-04988a864606-thumbnail.jpg)
Possible fossilized bone fragment
Fossil bone, composition primarily carbonate-hydroxylapatite [Ca₅(PO₄)₃(OH)]
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Chert (Holey Stone)
Microcrystalline Quartz (SiO2)
sedimentary
Chert Pebble
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Nodule)
Microcrystalline Quartz (SiO2)
sedimentary
Fossilized Brachiopod
Brachiopoda (e.g., Atrypa or Rhynchonellida)
fossil
Chert (Flint Nodules)
Microcrystalline Quartz (SiO2)
sedimentary