Definition
Siltstone can be defined as a fine-grained sedimentary rock which mainly consists of consolidated silt
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Discoverer
Unknown
Unknown
Etymology
From English word silt and stone and from Proto-Indo-European root sal and stainaz
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Not Applicable
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Clastic
Porphyritic
Color
Brown, Red, Reddish Brown
Black, Brown, Colourless, Green, Grey, Red, Rust, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Construction Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Commercial Uses
Raw material for the manufacture of mortar, Soil Conditioner
Creating Artwork, Gemstone, Jewelry
Types
Not Available
Rhomb Porphyry
Features
Available in Lots of Colors and Patterns, Easily splits into thin plates, Generally rough to touch, High silica content, Very fine grained rock
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Formation
Siltstone is a type of sedimentary rock which is formed from fine rock particles. As the particles of eroded rock travel along with water, the edges of the rock are worn-out by water into a rounded shape.
Porphyry is formed in two stages: the magma cools slowly deep within the crust or the magma is cools rapidly as it erupts from a volcano, creating small grains that are usually invisible to naked eye.
Mineral Content
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz, Sand, Silica, Silt
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Not Registered
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal
Irregular
Porosity
Highly Porous
Less Porous
Cleavage
Not Available
Imperfect
Specific Gravity
2.54-2.73
2.5-4
Transparency
Opaque
Translucent to Opaque
Density
2.6-2.7 g/cm3
2.5-2.52 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Water Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
Africa
Namibia, Nigeria, South Africa
Egypt, Ethiopia, Ghana, South Africa
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Others
Greenland
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, Cuba, Jamaica, USA
South America
Brazil
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Deposits in Oceania Continent
Australia
New South Wales, New Zealand
New South Wales, New Zealand, Western Australia
Siltstone vs Porphyry Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Siltstone vs Porphyry characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Siltstone and Properties of Porphyry. Learn more about Siltstone vs Porphyry in the next section. The interior uses of Siltstone include Decorative aggregates and Interior decoration whereas the interior uses of Porphyry include Decorative aggregates and Interior decoration. Due to some exceptional properties of Siltstone and Porphyry, they have various applications in construction industry. The uses of Siltstone in construction industry include Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate, Making natural cement, Raw material for the manufacture of mortar and that of Porphyry include Construction aggregate.
More about Siltstone and Porphyry
Here you can know more about Siltstone and Porphyry. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Siltstone and Porphyry consists of mineral content and compound content. The mineral content of Siltstone includes Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz, Sand, Silica, Silt and mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica. You can also check out the list of all Sedimentary Rocks. When we have to compare Siltstone vs Porphyry, the texture, color and appearance plays an important role in determining the type of rock. Siltstone is available in brown, red, reddish brown colors whereas, Porphyry is available in black, brown, colourless, green, grey, red, rust, white colors. Appearance of Siltstone is Rough and that of Porphyry is Dull. Properties of rock is another aspect for Siltstone vs Porphyry. Hardness of Siltstone and Porphyry is 6-7. The types of Siltstone are Not Available whereas types of Porphyry are Rhomb Porphyry. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Siltstone and Porphyry is white. The specific heat capacity of Siltstone is Not Available and that of Porphyry is Not Available. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Siltstone is heat resistant, impact resistant, pressure resistant, water resistant whereas Porphyry is heat resistant, impact resistant.
