Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Hornblendite is a type of igneous plutonic rock consisting mainly of amphibole hornblende and is a type of Amphibolite rock
Discoverer
Van Tooren
Unknown
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From German, Horn horn + blende
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Banded, Foliated, Massive
Color
Black, Brown, Green, Grey, White
Black, Brown, Green, Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Vesicular
Foliated
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Entryways, Flooring, Homes, Hotels, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
Landscaping
As Dimension Stone, Building houses or walls, Cobblestones, Construction Aggregate, for Road Aggregate, Landscaping, Production of Glass and Ceramics, Roadstone
Antiquity Uses
Artifacts, Sculpture
Artifacts, Sculpture, Small Figurines
Commercial Uses
Production of Lime, Soil Conditioner
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Igneous rock
Hornblende Gabbro and Hornblende Peridotite
Features
Host Rock for Lead
Clasts are smooth to touch, Matrix variable, Surfaces are often shiny
Archaeological Significance
Formation
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.
Hornblendite 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
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Amphibole, Calcite, Hornblade, Magnetite, Plagioclase, Wollastonite
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Medium to Coarse Grained
Fracture
Uneven
Irregular to Conchoidal
Streak
Bluish Black
White to Grey
Porosity
Very Less Porous
Less Porous
Luster
Subvitreous to Dull
Vitreous to Dull
Cleavage
Crenulation and Pervasive
-
Specific Gravity
2.86
2.5
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.85-3.07 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Africa
Namibia, Uganda
Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda
Europe
Germany, Hungary, Italy, Portugal, Spain
Germany, Greece, Iceland, Norway, Poland
Deposits in Western Continents
North America
USA
Canada, USA
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
South Australia, Western Australia