Definition
Theralite is a plutonic hylocrystalline igneous rock consisting of augite, olivine, calcic plagioclase and nepheline
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Discoverer
Unknown
Van Tooren
Etymology
From Greek to pursue
From Greek tephra, ashes from Indo-European base, to burn
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Phaneritic
Aphanitic to Porphyritic
Color
Dark Grey to Black
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Veined and Shiny
Vesicular
Interior Uses
Decorative Aggregates, Flooring, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Landscaping
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Production of Lime, Soil Conditioner
Types
Teschenite and Essexite
Igneous rock
Features
Smooth to touch
Host Rock for Lead
Archaeological Significance
Formation
Theralite 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.
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
Augite, Olivine, Plagioclase, Pyroxene
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Uneven, Splintery or Conchoidal
Uneven
Streak
White
Bluish Black
Porosity
Highly Porous
Very Less Porous
Luster
Waxy and Dull
Subvitreous to Dull
Cleavage
-
Crenulation and Pervasive
Specific Gravity
2.5-2.8
2.86
Transparency
Translucent to Opaque
Opaque
Density
2.7 g/cm3
2.8-2.9 g/cm3
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Africa
South Africa
Namibia, Uganda
Europe
Germany, Greece, Italy, Scotland, Turkey
Germany, Hungary, Italy, Portugal, Spain
Others
Greenland, Mid-Atlantic Ridge
-
Deposits in Western Continents
North America
Canada, USA
USA
South America
Bolivia, Brazil, Colombia, Venezuela
-
Deposits in Oceania Continent
Australia
New Zealand, Queensland
New Zealand, Western Australia