Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
Origin
Hawaii Islands
USA
Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
From the locality in Essex County, Massachusetts,US
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Earthy, Rough
Granular
Color
Black, Brown, Colourless, Green, Grey, Pink, White, Yellow
Dark Grey to Black
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Rough and Shiny
Banded
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
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, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
Types
Oceanite
Not Available
Features
Host Rock for Lead
Is one of the oldest rock, Smooth to touch
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
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.
Essexite is a type of igneous rock, which is usually dark grey to black plutonic rock. For the formation of essexite, suitable magma with exact composition of K, Ba, Rb, Cs, Sr should be produced.
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Uneven
Conchoidal
Streak
White, Greenish White or Grey
Black
Porosity
Less Porous
Highly Porous
Luster
Subvitreous to Dull
Not Available
Compressive Strength
Not Available
Cleavage
Imperfect
Not Available
Specific Gravity
2.75-2.92
Not Available
Transparency
Opaque
Opaque
Density
1.5-2.5 g/cm3
Not Available
Specific Heat Capacity
Not Available
Resistance
Heat Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
India, Russia
Africa
South Africa
South Africa
Europe
Iceland
Germany, Greece, Italy, Scotland, Turkey
Others
Not Yet Found
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
Not Yet Found
New Zealand, Queensland
All about Picrite and Essexite Properties
Know all about Picrite and Essexite properties here. All properties of rocks are important as they define the type of rock and its application. Picrite and Essexite belong to Igneous Rocks.Texture of Picrite is Earthy, Rough whereas that of Essexite is Granular. Picrite appears Rough and Shiny and Essexite appears Banded. The luster of Picrite is subvitreous to dull while that of Essexite is not available. Picrite is available in black, brown, colourless, green, grey, pink, white, yellow colors whereas Essexite is available in dark grey to black colors. The commercial uses of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo) and that of Essexite are cemetery markers, commemorative tablets, jewelry, sea defence, tombstones.