Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Travertine is a mineral consisting of layered calcium carbonate formed by deposition from spring waters
History
Origin
Brazil
Italy
Discoverer
Unknown
Marcus Vitruvius Pollio
Etymology
from French néphéline, from Greek nephelē
From Italian travertino a kind of building stone, from Tiburs, adjective from Tibur (Tivoli), in Italy
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Plutonic
-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic
Banded
Color
Black, Brown, Green, Grey, White
Beige, Black, Blue, Brown, Grey, Red, White, Yellow
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Skeletal
Fibrous
Architecture
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Jewellery, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Cemetery Markers, Creating Artwork, Gemstone, Jewelry, Paper Industry, Pottery
Types
Peralkaline Nephelinite
Thermal Travertine and Tufa
Features
Host Rock for Lead
Stalactites and stalagmites are formed from this rock, Surfaces are often shiny, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
Colosseum in Rome, Italy, Sacré Coeur in Paris, France, Trevi Fountain in Rome, Italy
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
Formation
Nephelinite 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.
Travertine is a type of sedimentary rock formed when a river carries or transports pieces of broken rock which then undergo sedimentation. They are then subjected to high temperature and pressure hence forming travertine rock.
Composition
Mineral Content
Clinopyroxene, Nepheline, Plagioclase
Calcite, Clay, Feldspar, Micas, Quartz
Compound Content
Ca, CaO, Carbon, Cl, MgO
Ca, NaCl, CaO, Oxygen
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Contact Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Physical Properties
Hardness
6.53-4
1
7
👆🏻
Grain Size
Fine Grained
Fine Grained
Fracture
Flat
Splintery
Streak
White
White
Porosity
Less Porous
Highly Porous
Luster
Vitreous to Metallic
Dull to Pearly
Compressive Strength
35.00 N/mm280.00 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
2.7
1
Specific Gravity
2.4-2.91.68
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.5-3 g/cm32.71 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.88 kJ/Kg K1.09 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Japan
China, Russia
Africa
Rwanda, Tanzania
-
Europe
-
Austria, Italy, Portugal, United Kingdom
Others
Hawaii Islands
-
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Colombia
Argentina, Bolivia, Ecuador
Deposits in Oceania Continent
Australia
-
-