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
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
Discoverer
Unknown
Unknown
Etymology
From the Middle High German verb gneist (to spark; so called because the rock glitters)
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Banded, Foliated, Platy
Vesicular
Color
Black, Brown, Pink, Red, White
Black, Brown, Dark Grey to Black, Red
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Foliated
Glassy and Vesicular
Interior Uses
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone
Cement Manufacture, Construction Aggregate, for Road Aggregate, In landscaping and drainage works
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
As a traction material on snow-covered roads, Creating Artwork, High-temperature insulation, In gas barbecue grills
Types
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Basaltic Scoria and Andesitic Scoria
Features
Generally rough to touch, Is one of the oldest rock
Available in Lots of Colors and Patterns, Generally rough to touch, Surfaces are often shiny
Archaeological Significance
Famous Monuments
Konark Sun Temple in India, Washington Monument, US
-
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.
Scoria forms when magma containing huge amount of dissolved gas flows from a volcano during an eruption.
Mineral Content
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Ca, NaCl
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, Glacier Erosion
Grain Size
Medium to Coarse Grained
Fine Grained
Fracture
Irregular
Conchoidal
Porosity
Very Less Porous
Highly Porous
Luster
Dull
Subvitreous to Dull
Specific Gravity
2.5-2.7
-9999
Transparency
Translucent to Opaque
Opaque
Density
2.6-2.9 g/cm3
-9999 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
Afghanistan, Indonesia, Japan, Russia
Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Ethiopia, Kenya, Tanzania
Europe
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
Greece, Hungary, Iceland, Italy, Turkey
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA
South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria
New Zealand, Western Australia
Gneiss vs Scoria 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 Scoria characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gneiss and Properties of Scoria. Learn more about Gneiss vs Scoria in the next section. The interior uses of Gneiss include Countertops, Decorative aggregates, Flooring and Interior decoration whereas the interior uses of Scoria include Decorative aggregates and Interior decoration. Due to some exceptional properties of Gneiss and Scoria, they have various applications in construction industry. The uses of Gneiss in construction industry include As dimension stone and that of Scoria include Cement manufacture, Construction aggregate, For road aggregate, In landscaping and drainage works.
More about Gneiss and Scoria
Here you can know more about Gneiss and Scoria. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gneiss and Scoria 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 Scoria includes Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica. You can also check out the list of all Metamorphic Rocks. When we have to compare Gneiss vs Scoria, 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, Scoria is available in black, brown, dark grey to black, red colors. Appearance of Gneiss is Foliated and that of Scoria is Glassy and Vesicular. Properties of rock is another aspect for Gneiss vs Scoria. The hardness of Gneiss is 7 and that of Scoria is 5-6. The types of Gneiss are Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss. whereas types of Scoria are Basaltic Scoria and Andesitic Scoria. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Gneiss and Scoria is white. The specific heat capacity of Gneiss is 0.70 kJ/Kg K and that of Scoria is 0.84 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 Scoria is heat resistant, impact resistant, pressure resistant, wear resistant.