Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Hawaiite is volcanic rock that resembles basalt. It is an olivine basalt with intermediate composition between alkali olivine and mugearite
History
Origin
Hawaii Islands
Hawaii Islands
Discoverer
Unknown
Joseph Iddings
Etymology
From Greek pikros bitter + -ite, 19th century
From Hawaii Islands
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
Texture
Earthy, Rough
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Black, Brown, Green, Grey, Pink, White, Yellow
Black, Brown, Light to Dark Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Rough and Shiny
Dull and Soft
Architecture
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
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-
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Other Uses
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Creating Artwork, Sea Defence
Types
Oceanite
Volcanic rock
Features
Host Rock for Lead
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
Easter Island in the Polynesian Triangle, Pacific Ocean
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
Picrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Hawaiite is a fine-grained, hard rock that forms when bits of lava shoot out of volcanoes and reach the Earth's surface.
Composition
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Olivine, Plagioclase, Pyroxene
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Impact Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering
Biological Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
-
Physical Properties
Hardness
6.86
1
7
👆🏻
Grain Size
Fine Grained
-
Fracture
Uneven
Conchoidal
Streak
White, Greenish White or Grey
-
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
-
Compressive Strength
189.00 N/mm237.40 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
2.1
-
Specific Gravity
2.75-2.92-9999
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
1.5-2.5 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.88 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
India, Russia
Africa
South Africa
South Africa
Europe
Iceland
Iceland
Others
-
Hawaii Islands
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Brazil
Deposits in Oceania Continent
Australia
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-