Definition
Rhomb-porphyry is a porphyritic igneous rock with abundant wedge or lens shaped anorthoclase or feldspar phenocrysts
Carbonatite is intrusive or extrusive igneous rock which is defined by mineralogic composition, consisting of greater than 50 percent carbonate minerals
Discoverer
Unknown
Unknown
Etymology
From Latin term that means purple
From any intrusive igneous rock, having a majority of carbonate minerals
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Granular, Poikiloblastic
Color
Black, Brown, Green, Grey, Pink, White
Black, Brown, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Rough
Dull, Banded and Foilated
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
Commercial Uses
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Metallurgical Flux, Soil Conditioner, Source of Magnesia (MgO)
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux
Types
Igneous rock
Carbonatite
Features
Host Rock for Lead
Available in lots of colors, Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Formation
Rhomb-porphyry 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.
Carbonatites are intrusive or extrusive igneous rocks which are defined by mineralogic composition consisting of greater than 50 percent carbonate minerals and are formed due to low degrees of partial melting of rocks.
Mineral Content
Alkali feldspar, Biotite, Plagioclase, Pyroxene
Ancylite, Apatite, Barite, Fluorite, Magnetite, Natrolite, Sodalite
Compound Content
CaO, Cl, MgO
CaO, Carbon Dioxide, Sodium Oxide
Types of Metamorphism
Impact Metamorphism
Burial Metamorphism, Contact 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, Water Erosion
Chemical Erosion, Wind Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Porosity
Very Less Porous
Less Porous
Luster
Subvitreous to Dull
Subvitreous to Dull
Specific Gravity
2.86
2.86-2.87
Transparency
Translucent
Opaque
Density
2.8-2.9 g/cm3
2.84-2.86 g/cm3
Resistance
Heat Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant, Water Resistant
Deposits in Eastern Continents
Asia
-
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
-
Namibia, Nigeria, South Africa
Europe
Bulgaria
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Deposits in Western Continents
North America
USA
Canada, USA
Deposits in Oceania Continent
Australia
-
New South Wales, New Zealand