Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Lherzolite is a type of ultramafic igneous rock which contains essential olivine and clinopyroxene and orthopyroxene in equal proportions
History
Origin
Hawaii Islands
France
Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
From the Lherz Massif, an alpine peridotite complex, at Étang de Lers, near Massat in the French Pyrenees; Lherz is the archaic spelling of this location
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Earthy, Rough
Grenue
Color
Black, Brown, Green, Grey, Pink, White, Yellow
Black, Dark Greenish - Grey, Green, Pink, Purple
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Rough and Shiny
Glassy, Vesicular and Foilated
Architecture
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Entryways, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, 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.
Landscaping, Manufacture of Magnesium and Dolomite Refractories, Used for flooring, stair treads, borders and window sills.
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Sculpture
Other Uses
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
As armour rock for sea walls, Source of Magnesia (MgO), Used in aquariums
Types
Oceanite
Garnet Lherzolite
Features
Host Rock for Lead
Host Rock for Lead
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
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.
Lherzolite 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.
Composition
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Harzburgite, Olivine, Pyroxene, Pyrrhotite
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
CaO, Cr, Chromium(III) Oxide, MgO
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
6.86.5
1
7
👆🏻
Grain Size
Fine Grained
Fine Grained
Fracture
Uneven
Conchoidal
Streak
White, Greenish White or Grey
White
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Subvitreous to Dull
Compressive Strength
189.00 N/mm2290.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Perfect
Toughness
2.1
2.7
Specific Gravity
2.75-2.922.86
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
1.5-2.5 g/cm32.8-2.9 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.88 kJ/Kg K0.95 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
Russia, South Korea
Africa
South Africa
Western Africa
Europe
Iceland
United Kingdom
Others
-
-
Deposits in Western Continents
North America
Canada, USA
USA
South America
Brazil
-
Deposits in Oceania Continent
Australia
-
Central Australia, Western Australia