Definition
Rhomb-porphyry is a porphyritic igneous rock with abundant wedge or lens shaped anorthoclase or feldspar phenocrysts
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
History
Origin
-
-
Discoverer
Unknown
Unknown
Etymology
From Latin term that means purple
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Vesicular
Color
Black, Brown, Green, Grey, Pink, White
Black, Brown, Dark Grey to Black, Red
Maintenance
Less
More
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Rough
Glassy and Vesicular
Architecture
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
Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
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
Cement Manufacture, Construction Aggregate, for Road Aggregate, In landscaping and drainage works
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Other Uses
Commercial Uses
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Metallurgical Flux, Soil Conditioner, Source of Magnesia (MgO)
As a traction material on snow-covered roads, Creating Artwork, High-temperature insulation, In gas barbecue grills
Types
Igneous rock
Basaltic Scoria and Andesitic Scoria
Features
Host Rock for Lead
Available in Lots of Colors and Patterns, Generally rough to touch, Surfaces are often shiny
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
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.
Scoria forms when magma containing huge amount of dissolved gas flows from a volcano during an eruption.
Composition
Mineral Content
Alkali feldspar, Biotite, Plagioclase, Pyroxene
Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica
Compound Content
CaO, Cl, MgO
Ca, NaCl
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Impact Metamorphism
Burial Metamorphism, Cataclastic 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, Coastal Erosion, Glacier Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Physical Properties
Hardness
5-5.55-6
1
7
👆🏻
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Streak
White
White
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Subvitreous to Dull
Compressive Strength
310.00 N/mm270.00 N/mm2
0.15
450
👆🏻
Cleavage
Perfect
Perfect
Toughness
2.7
2.1
Specific Gravity
2.86-9999
0
8.4
👆🏻
Transparency
Translucent
Opaque
Density
2.8-2.9 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
-
Afghanistan, Indonesia, Japan, Russia
Africa
-
Ethiopia, Kenya, Tanzania
Europe
Bulgaria
Greece, Hungary, Iceland, Italy, Turkey
Others
-
-
Deposits in Western Continents
North America
USA
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA
South America
-
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
-
New Zealand, Western Australia