Definition
Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance
Jasperoid is a rare, peculiar type of metasomatic alteration of rocks
History
Origin
France
USA
Discoverer
Unknown
Unknown
Etymology
From Latin varius, speckled, variegated
From silica, the main mineral content of Jasperoid
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
-
Other Categories
Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Earthy
Color
Black, Brown, Light to Dark Grey
Black, Brown, Green, Grey, Pink, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull and Soft
Glassy or Pearly
Architecture
Interior Uses
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics, Serves as an Oil and Gas Reservoir rock
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Jewellery, Monuments, Sculpture
Other Uses
Commercial Uses
Cemetery Markers, Creating Artwork
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)
Types
Metamorphic rock
-
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Host Rock for Lead, Traps for subsurface fluids like Oil and Natural Gas., Zinc and Copper Deposits
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
Formation
Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.
Jasperoid is a rare and peculiar type of metasomatic alteration of rocks. It is formed by extreme alteration of wall rocks within a shear zone which may occur in sediments, andesites, trachytes and basalts.
Composition
Mineral Content
Olivine, Plagioclase, Pyroxene
Clay Minerals, Pyrite, Quartz, Sulfides
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
NaCl, CaO, Carbon Dioxide, Magnesium Carbonate, MgO
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Erosion
✔
✘
✔
✘
Types of Erosion
-
-
Physical Properties
Hardness
63.5-4
1
7
👆🏻
Grain Size
-
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Streak
White to Grey
White
Porosity
Less Porous
Less Porous
Luster
-
Vitreous and Pearly
Compressive Strength
37.50 N/mm2140.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Perfect
Toughness
2.3
1
Specific Gravity
2.8-32.8-3
0
8.4
👆🏻
Transparency
Opaque
Transparent to Translucent
Density
2.9-3.1 g/cm32.8-2.9 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India
Africa
South Africa
Morocco, Namibia
Europe
Iceland
Austria, Italy, Romania, Spain, Switzerland
Others
-
-
Deposits in Western Continents
North America
Canada, USA
Mexico, USA
South America
Brazil
Brazil, Colombia
Deposits in Oceania Continent
Australia
-
New South Wales, Queensland, Yorke Peninsula