Ironstone
Rock made of siderite, limonite, hematite, chamosite
Common
A sedimentary rock rich enough in iron minerals to be smelted, grey when fresh and brown where it weathers. Most British iron came from it before richer ores took over.
Rock
- Kind of rock
- Chemical sedimentary rock
- Rock family
- Sandstone, shale and clay
- Also contains
- Magnetite
- Deposits
- Ironstone beds
- Metals
- Iron
- How it forms
- Laid down directly as an iron-rich sediment, or made when iron minerals replace another sediment; the Precambrian kind is banded iron formation.
- Uses
- Iron ore, historically; now too thin and too poor for most mines.
Identity
- Also known as
- Tiger iron (banded form)
Crystallography
- Habits
- Massive, Nodular
Physical properties
- Luster
- Dull, Earthy
- Colors
- gray, brown, reddish brown
- Transparency
- Opaque
Geology
- Origins
- Sedimentary
- Host rocks
- Sandstone, shale and clay
- Geography
- England (Cleveland, North Yorkshire), France (Lorraine), Luxembourg
Classification
- Rarity
- Common
- Gem quality
- No
Sources
- Ironstone. Wikipedia.
- Cleveland Ironstone Formation. Wikipedia.
- Minette (ore). Wikipedia.
- C. R. Hallsworth, R. W. O’B. Knox, BGS Rock Classification Scheme, Volume 3: Classification of sediments and sedimentary rocks (Research Report RR 99-03). British Geological Survey, 1999.
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