Definition
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks
Rapakivi Granite is a hornblende-biotite Granite containing large rounded crystals of orthoclase which are mantled with oligoclase
Origin
Unknown
Finland, Europe
Discoverer
Unknown
Jakob Sederholm
Etymology
From the Middle High German verb gneist (to spark; so called because the rock glitters)
From Finnish Rapakivi which stands for crumbly rock
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Not Applicable
Plutonic
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Banded, Foliated, Platy
Granular, Phaneritic
Color
Black, Brown, Pink, Red, White
Black, Grey, Orange, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Foliated
Veined or Pebbled
Interior Uses
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Bathrooms, Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Office Buildings, Paving Stone, Resorts
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
As Dimension Stone
As Dimension Stone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Laboratory bench tops, Tombstones
Types
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite and Hybrid Granite
Features
Generally rough to touch, Is one of the oldest rock
Available in Lots of Colors and Patterns, It is One of the Oldest, Strongest and Hardest Rock
Archaeological Significance
Famous Monuments
Konark Sun Temple in India, Washington Monument, US
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Not Yet Used
Used
Formation
Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.
Granite is an igneous rock which is very hard, crystalline and is visibly homogeneous in texture and forms by melting of continental rocks
Mineral Content
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Coarse Grained
Large and Coarse Grained
Fracture
Irregular
Not Available
Porosity
Very Less Porous
Less Porous
Luster
Dull
Dull to Grainy with Sporadic parts Pearly and Vitreous
Cleavage
Poor
Not Available
Toughness
1.2
Not Available
Specific Gravity
2.5-2.7
2.6-2.7
Transparency
Translucent to Opaque
Opaque
Density
2.6-2.9 g/cm3
2.6-2.8 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic, Venezuela
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
Canada, USA
South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Not Yet Found
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria
Not Yet Found
Gneiss vs Rapakivi Granite 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. Gneiss vs Rapakivi Granite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gneiss and Properties of Rapakivi Granite. Learn more about Gneiss vs Rapakivi Granite in the next section. The interior uses of Gneiss include Countertops, Decorative aggregates, Flooring and Interior decoration whereas the interior uses of Rapakivi Granite include Bathrooms, Countertops, Decorative aggregates, Entryways, Floor tiles, Flooring, Homes, Hotels, Interior decoration, Kitchens and Stair treads. Due to some exceptional properties of Gneiss and Rapakivi Granite, they have various applications in construction industry. The uses of Gneiss in construction industry include As dimension stone and that of Rapakivi Granite include As dimension stone.
More about Gneiss and Rapakivi Granite
Here you can know more about Gneiss and Rapakivi Granite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gneiss and Rapakivi Granite consists of mineral content and compound content. The mineral content of Gneiss includes Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon and mineral content of Rapakivi Granite includes Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz. You can also check out the list of all Metamorphic Rocks. When we have to compare Gneiss vs Rapakivi Granite, the texture, color and appearance plays an important role in determining the type of rock. Gneiss is available in black, brown, pink, red, white colors whereas, Rapakivi Granite is available in black, grey, orange, pink, white colors. Appearance of Gneiss is Foliated and that of Rapakivi Granite is Veined or Pebbled. Properties of rock is another aspect for Gneiss vs Rapakivi Granite. The hardness of Gneiss is 7 and that of Rapakivi Granite is 6-7. The types of Gneiss are Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss. whereas types of Rapakivi Granite are Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite and Hybrid Granite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Gneiss and Rapakivi Granite is white. The specific heat capacity of Gneiss is Not Available and that of Rapakivi Granite is 0.79 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Gneiss is heat resistant, pressure resistant, scratch resistant, wear resistant whereas Rapakivi Granite is heat resistant, wear resistant.