Jasper
Rock made of chalcedony
Common · SiO₂ with iron oxides
An opaque, impure chalcedony or fine-grained chert holding up to a fifth of foreign matter, mostly hematite and iron hydroxides, which give it its reds, browns and yellows. Rarely of one colour: usually striped, spotted or flamed. Found in beds, in veins and nodules of iron ores, and as river pebbles. Blue-dyed jasper has been sold as "Swiss lapis".
Rock
- Kind of rock
- Chemical sedimentary rock
- Rock family
- Limestone and chalk
- Texture
- cryptocrystalline (crystals too small to see under a lens)
- Also contains
- Hematite, Goethite
- Deposits
- Banded iron formation deposit, Ironstone beds
- How it forms
- A chert coloured by iron oxides, in beds, veins and nodules; its red bands alternate with iron oxide in banded iron formation.
Identity
- Formula
- SiO₂ with iron oxides
- Chemical class
- Silicate
- Mineral group
- Agate, Amethyst, Bloodstone, Carnelian, Chalcedony, Citrine, Moss Agate, Onyx, Quartz, Rose Quartz, Smoky Quartz, Tiger's Eye
- Also known as
- Orbicular jasper, Dallasite
- Used in alchemy
- Jasper Powder
Crystallography
- Crystal system
- Trigonal
- Habits
- Massive, Nodular
- Fracture
- Conchoidal
Physical properties
- Mohs hardness
- 6.5
- Density
- 2.65 g/cm³
- Luster
- Dull
- Colors
- red, brown, yellow, green, multicolored
- Streak
- white
- Transparency
- Opaque
Geology
- Origins
- Sedimentary, Metamorphic, Hydrothermal
- Host rocks
- Volcanic rock, Limestone and chalk, Sandstone, shale and clay
- Associated minerals
- Chalcedony, Agate, Opal, Hematite
- Geography
- worldwide
Classification
- Rarity
- Common
- Gem quality
- Yes
Arcane properties
- Affinity
- Earth, Life
- Effects
- Healing
- Planar origin
- Material Plane
Sources
- Jasper. Mindat.org (Hudson Institute of Mineralogy).
- Jasper. Gemdat.org (Hudson Institute of Mineralogy).
- Chert. 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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