Definition
Icelandite belongs to volcanic igneous rocks which is rich in iron and belongs to andesite rock
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Discoverer
Ian S. E. Carmichael
Van Tooren
Etymology
From its origin place near Cenozoic volcano near the parsonage Þingmúli in East Iceland
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
Aphanitic to Porphyritic
Aphanitic to Porphyritic
Color
Bluish - Grey, Grey, Pink, Yellow
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Vesicular
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
Office Buildings, Roof Tiles
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
Cobblestones, Construction Aggregate, for Road Aggregate
Landscaping
Antiquity Uses
Artifacts, Jewellery, Sculpture, Small Figurines
Artifacts, Sculpture
Commercial Uses
Cemetery Markers, Creating Artwork
Production of Lime, Soil Conditioner
Types
Intermediate volcanic rock
Igneous rock
Features
Generally rough to touch, High silica content, Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
Formation
Icelandite 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
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Compound Content
Silicon 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
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Grain Size
Very fine-grained
Medium to Fine Coarse Grained
Streak
White
Bluish Black
Porosity
Less Porous
Very Less Porous
Luster
Vitreous
Subvitreous to Dull
Cleavage
-
Crenulation and Pervasive
Specific Gravity
2.5-2.8
2.86
Transparency
Opaque
Opaque
Density
2.11-2.36 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
India, Indonesia, Japan, Nepal, South Korea
-
Africa
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
Namibia, Uganda
Europe
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Germany, Hungary, Italy, Portugal, Spain
Deposits in Western Continents
North America
Mexico, USA
USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
-
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
New Zealand, Western Australia