Definition
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
Trondhjemite is a leucocratic (light-colored) intrusive igneous rock. It is a variety of tonalite in which the plagioclase is mostly in the form of oligoclase. Trondhjemites are sometimes known as plagiogranites.
Discoverer
Unknown
Unknown
Etymology
From French schiste, Greek skhistos i.e. split
From Trondheim, Norway
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Foliated, Platy
Phaneritic
Color
Black, Blue, Brown, Dark Brown, Green, Grey, Silver
Black, Brown, Light to Dark Grey, White
Durability
Durable
Durable
Appearance
Layered and Shiny
Banded and Foilated
Interior Uses
Decorative Aggregates, Floor Tiles, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
-
Curbing
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone
As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Used in aquariums, Writing Slates
Cemetery Markers, Creating Artwork
Types
Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.
Intermediate intrusive rock
Features
Easily splits into thin plates, Smooth to touch
Is one of the oldest rock, Typically speckled black and white.
Archaeological Significance
Formation
Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.
When alkali feldspar is extracted from granite, it changes to granitoid and later, it becomes trondhjemite with quartz as major mineral.
Mineral Content
Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
Compound Content
CaO, Carbon Dioxide, MgO
NaCl, CaO, MgO, Silicon Dioxide
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Streak
White
Bluish Black
Porosity
Highly Porous
Very Less Porous
Luster
Shiny
Subvitreous to Dull
Specific Gravity
2.5-2.9
2.86-3
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.73 g/cm3
Resistance
Impact Resistant, Pressure Resistant, Water Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
-
Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
Egypt
Europe
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
Finland, Germany, Italy, Romania, Sweden, Turkey
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
USA
South America
Brazil, Colombia, Guyana
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland
New Zealand, South Australia, Western Australia
Schist vs Trondhjemite 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. Schist vs Trondhjemite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Schist and Properties of Trondhjemite. Learn more about Schist vs Trondhjemite in the next section. The interior uses of Schist include Decorative aggregates, Floor tiles and Interior decoration whereas the interior uses of Trondhjemite include Decorative aggregates, Entryways, Flooring, Homes and Interior decoration. Due to some exceptional properties of Schist and Trondhjemite, they have various applications in construction industry. The uses of Schist in construction industry include As dimension stone, Building houses or walls, Cement manufacture, For road aggregate, Roadstone and that of Trondhjemite include As dimension stone, Cement manufacture, Cobblestones, Construction aggregate, For road aggregate.
More about Schist and Trondhjemite
Here you can know more about Schist and Trondhjemite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Schist and Trondhjemite consists of mineral content and compound content. The mineral content of Schist includes Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc and mineral content of Trondhjemite includes Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon. You can also check out the list of all Metamorphic Rocks. When we have to compare Schist vs Trondhjemite, the texture, color and appearance plays an important role in determining the type of rock. Schist is available in black, blue, brown, dark brown, green, grey, silver colors whereas, Trondhjemite is available in black, brown, light to dark grey, white colors. Appearance of Schist is Layered and Shiny and that of Trondhjemite is Banded and Foilated. Properties of rock is another aspect for Schist vs Trondhjemite. The hardness of Schist is 3.5-4 and that of Trondhjemite is 6-7. The types of Schist are Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist. whereas types of Trondhjemite are Intermediate intrusive rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Schist is white while that of Trondhjemite is bluish black. The specific heat capacity of Schist is 0.70 kJ/Kg K and that of Trondhjemite 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.Schist is impact resistant, pressure resistant, water resistant whereas Trondhjemite is heat resistant, pressure resistant, wear resistant.