![Banded Iron Formation (BIF) / Red Jasper with Hematite (Ferruginous Chert (primarily Quartz [SiO2] and Hematite [Fe2O3])) — sedimentary](https://media.rock.id/be70c25f-a8d5-4bcc-b05a-24698ef01334-compressed.jpg)
sedimentary
Banded Iron Formation (BIF) / Red Jasper with Hematite
Ferruginous Chert (primarily Quartz [SiO2] and Hematite [Fe2O3])
Hardness: 6.5-7 (Mohs); Color: deep red, black, and silver/grey; Luster: vitreous to sub-metallic; Crystal Structure: microcrystalline/cryptocrystalline; Dense and heavy due to iron content.
- Hardness
- 6
- Color
- deep red, black, and silver/grey
- Luster
- vitreous to sub-metallic
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs); Color: deep red, black, and silver/grey; Luster: vitreous to sub-metallic; Crystal Structure: microcrystalline/cryptocrystalline; Dense and heavy due to iron content.
Formation & geological history
Formed in marine environments during the Precambrian era (approx. 2.4 to 1.8 billion years ago) through the precipitation of iron and silica as oxidation levels in the atmosphere changed due to photosynthesis by cyanobacteria.
Uses & applications
Major industrial source of iron ore globally; used as semi-precious gemstones in jewelry (Jasper/Hematite) and as decorative ornamental stones or paperweights for collectors.
Geological facts
These rocks represent the 'Great Oxygenation Event' in Earth's history, capturing the moment the atmosphere first became oxygen-rich. They are most commonly found in ancient cratons like the Canadian Shield or Western Australia.
Field identification & locations
Identify by alternating red and black layers, high density/weight, and its ability to scratch glass. Commonly found in Great Lakes regions (Minnesota/Michigan), Australia, Brazil, and South Africa.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary