Definition
Minette is a variety of Lamprophyre and is porphyritic alkaline igneous rock which is mainly dominated by biotite and potassic feldspar
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Discoverer
Unknown
Van Tooren
Etymology
From French mine ore, mine + ette
From Greek tephra, ashes from Indo-European base, to burn
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
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Porphyritic
Aphanitic to Porphyritic
Color
Black, Bluish - Grey, Brown, Dark Greenish - Grey, Green, Grey
Black, Brown, Colourless, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull, Banded and Foilated
Vesicular
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Landscaping
Medical Industry
Taken as a Supplement for Calcium or Magnesium
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Sculpture
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)
Production of Lime, Soil Conditioner
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
Host Rock for Lead
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
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.
Tephrite 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.
Mineral Content
Amphibole, Carbonate, Garnet, Micas, Olivine, Phlogopite, Pyroxene
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Grain Size
Fine to Coarse Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Uneven
Streak
White
Bluish Black
Porosity
Very Less Porous
Very Less Porous
Luster
Subvitreous to Dull
Subvitreous to Dull
Compressive Strength
Not Available
Cleavage
Conchoidal
Crenulation and Pervasive
Toughness
Not Available
2.4
Specific Gravity
2.86-2.87
2.86
Transparency
Translucent to Opaque
Opaque
Density
2.95-2.96 g/cm3
2.8-2.9 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Russia
Not Yet Found
Africa
Angola, Botswana, Cameroon, Ethiopia, South Africa
Namibia, Uganda
Europe
England, Hungary, Iceland, United Kingdom
Germany, Hungary, Italy, Portugal, Spain
Others
Antarctica, Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, Mexico, USA
USA
South America
Argentina, Colombia, Ecuador
Not Yet Found
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, South Australia, Western Australia
New Zealand, Western Australia
All about Minette and Tephrite Properties
Know all about Minette and Tephrite properties here. All properties of rocks are important as they define the type of rock and its application. Minette and Tephrite belong to Igneous Rocks.Texture of Minette is Porphyritic whereas that of Tephrite is Aphanitic to Porphyritic. Minette appears Dull, Banded and Foilated and Tephrite appears Vesicular. The luster of Minette and Tephrite is subvitreous to dull. Minette is available in black, bluish - grey, brown, dark greenish - grey, green, grey colors whereas Tephrite is available in black, brown, colourless, green, grey, white colors. The commercial uses of Minette and Tephrite are an oil and gas reservoir, as a feed additive for livestock, gemstone, metallurgical flux, production of lime, soil conditioner, source of magnesia (mgo).