Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Novaculite is a dense, hard, fine-grained, siliceous metamorpic rock which is a type of chert that breaks with conchoidal fracture
Discoverer
Van Tooren
Unknown
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From Latin word novacula, for razor stone
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Volcanic
Not Applicable
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Banded, Glassy, Rough, Vitreous
Color
Black, Brown, Colourless, Green, Grey, White
Black, Brown, Green, Grey, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Vesicular
Glassy or Pearly
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
Landscaping
Arrowheads, Building houses or walls, Cement Manufacture, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives, Landscaping, Making natural cement, Production of Glass and Ceramics, Rail Track Ballast, Roadstone, Spear Points, Used to sharpen metal tools and weapons
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Sculpture
Artifacts, Monuments
Commercial Uses
Production of Lime, Soil Conditioner
Cemetery Markers, Gemstone, In aquifers, In fire-starting tools, Jewelry, Manufacture of tools, Pebbles are used in ball mills to grind in ceramics industry, To determine the gold content of jewelry
Types
Not Available
Not Available
Features
Host Rock for Lead
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Used
Not Yet Used
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.
Novaculite forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The formation of Novaculite can be either of chemical or biological origin.
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Quartz, Silicon
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Ca, Silicon Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Not Applicable
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Uneven
Conchoidal
Streak
Bluish Black
Colorless
Porosity
Very Less Porous
Less Porous
Luster
Subvitreous to Dull
Waxy and Dull
Cleavage
Crenulation and Pervasive
Non-Existent
Specific Gravity
2.86
2.5-2.7
Transparency
Opaque
Translucent to Opaque
Density
2.8-2.9 g/cm3
2.7 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Not Yet Found
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
Namibia, Uganda
Kenya, Morocco, South Africa, Tanzania
Europe
Germany, Hungary, Italy, Portugal, Spain
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Not Yet Found
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
USA
Canada, Mexico, USA
South America
Not Yet Found
Bolivia, Brazil
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New South Wales, Queensland, South Australia, Western Australia
All about Tephrite and Novaculite Properties
Know all about Tephrite and Novaculite properties here. All properties of rocks are important as they define the type of rock and its application. Tephrite belongs to Igneous Rocks while Novaculite belongs to Sedimentary Rocks.Texture of Tephrite is Aphanitic to Porphyritic whereas that of Novaculite is Banded, Glassy, Rough, Vitreous. Tephrite appears Vesicular and Novaculite appears Glassy or Pearly. The luster of Tephrite is subvitreous to dull while that of Novaculite is waxy and dull. Tephrite is available in black, brown, colourless, green, grey, white colors whereas Novaculite is available in black, brown, green, grey, red, white colors. The commercial uses of Tephrite are production of lime, soil conditioner and that of Novaculite are cemetery markers, gemstone, in aquifers, in fire-starting tools, jewelry, manufacture of tools, pebbles are used in ball mills to grind in ceramics industry, to determine the gold content of jewelry.