Definition
Minette is a variety of Lamprophyre and is porphyritic alkaline igneous rock which is mainly dominated by biotite and potassic feldspar
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
Discoverer
Unknown
Unknown
Etymology
From French mine ore, mine + ette
From the locality in Essex County, Massachusetts,US
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Porphyritic
Granular
Color
Black, Bluish - Grey, Brown, Dark Greenish - Grey, Green, Grey
Dark Grey to Black
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull, Banded and Foilated
Banded
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Medical Industry
Taken as a Supplement for Calcium or Magnesium
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
Types
Minette, Alnoite, Camptonite, Monchiquite, Fourchite, Vogesite, Appinite and Spessartite
Not Available
Features
Always found as volcanic pipes over deep continental crust, Host rock for Diamond, Is one of the oldest rock, Surfaces are often shiny
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
Used
Not Used
Petroglyphs
Used
Not Used
Formation
Minette formation takes place deep beneath the Earth’s surface at around 150 to 450 kms, and are erupted rapidly and violently.
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
Amphibole, Carbonate, Garnet, Micas, Olivine, Phlogopite, Pyroxene
Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion, Wind Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Grain Size
Fine to Coarse Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Not Available
Cleavage
Conchoidal
Not Available
Toughness
Not Available
1.6
Specific Gravity
2.86-2.87
Not Available
Transparency
Translucent to Opaque
Opaque
Density
2.95-2.96 g/cm3
Not Available
Resistance
Heat Resistant, Impact Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Russia
India, Russia
Africa
Angola, Botswana, Cameroon, Ethiopia, South Africa
South Africa
Europe
England, Hungary, Iceland, United Kingdom
Germany, Greece, Italy, Scotland, Turkey
Others
Antarctica, Greenland
Greenland
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Argentina, Colombia, Ecuador
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, South Australia, Western Australia
New Zealand, Queensland