Definition
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
Conglomerate is a sedimentary rock which forms from rounded gravel and boulder sized clasts which are cemented together in a matrix
Discoverer
Unknown
Unknown
Etymology
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
From Latin conglomeratus, to roll together, i.e. from com together + glomerare to gather into a ball, from glomus (genitive glomeris) a ball
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Porphyritic
Clastic
Color
Black, Brown, Green, Grey, Red, Rust, White
Beige, Black, Brown, Buff, Light to Dark Grey, Orange, Rust, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Shiny and Rounded
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes
Exterior Uses
Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Roof Tiles
Other Architectural Uses
Curbing
Curbing
Construction Industry
Construction Aggregate
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Roadstone
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Cemetery Markers, In aquifers, Tombstones
Types
Rhomb Porphyry
Orthoconglomerate and Paraconglomerate
Features
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
Clasts are smooth to touch, Is one of the oldest rock, Matrix variable
Archaeological Significance
Formation
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.
Conglomerate forms where sediments consisting mainly of pebble and cobble-size clasts at least two millimeters in diameter starts accumulating.
Mineral Content
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
Clay, Sand, Silica, Silt
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
NaCl, CaO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
-
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion
Grain Size
Fine Grained
Coarse Grained
Fracture
Irregular
Uneven
Porosity
Less Porous
Highly Porous
Specific Gravity
2.5-4
2.86-2.88
Transparency
Translucent to Opaque
Opaque
Density
2.5-2.52 g/cm3
1.7-2.3 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
Egypt, Ethiopia, Ghana, South Africa
Namibia, Nigeria, South Africa
Europe
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Others
Greenland
Greenland
Deposits in Western Continents
North America
Canada, Cuba, Jamaica, USA
Canada, USA
South America
Bolivia, Brazil, Colombia, Ecuador, Paraguay
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Western Australia
New South Wales, New Zealand
Porphyry vs Conglomerate 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. Porphyry vs Conglomerate characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Porphyry and Properties of Conglomerate. Learn more about Porphyry vs Conglomerate in the next section. The interior uses of Porphyry include Decorative aggregates and Interior decoration whereas the interior uses of Conglomerate include Decorative aggregates, Floor tiles and Homes. Due to some exceptional properties of Porphyry and Conglomerate, they have various applications in construction industry. The uses of Porphyry in construction industry include Construction aggregate and that of Conglomerate include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate, Roadstone.
More about Porphyry and Conglomerate
Here you can know more about Porphyry and Conglomerate. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Porphyry and Conglomerate consists of mineral content and compound content. The mineral content of Porphyry includes Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica and mineral content of Conglomerate includes Clay, Sand, Silica, Silt. You can also check out the list of all Igneous Rocks. When we have to compare Porphyry vs Conglomerate, the texture, color and appearance plays an important role in determining the type of rock. Porphyry is available in black, brown, green, grey, red, rust, white colors whereas, Conglomerate is available in beige, black, brown, buff, light to dark grey, orange, rust, white, yellow colors. Appearance of Porphyry is Dull and that of Conglomerate is Shiny and Rounded. Properties of rock is another aspect for Porphyry vs Conglomerate. The hardness of Porphyry is 6-7 and that of Conglomerate is 2-3. The types of Porphyry are Rhomb Porphyry whereas types of Conglomerate are Orthoconglomerate and Paraconglomerate. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Porphyry and Conglomerate is white. The specific heat capacity of Porphyry is 0.71 kJ/Kg K and that of Conglomerate is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Porphyry is heat resistant, impact resistant whereas Conglomerate is heat resistant.