Definition
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.
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Origin
Tonale, Italy
France
Discoverer
Unknown
Unknown
Etymology
From Trondheim, Norway
From French, Latin lignum wood + -ite1
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft 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
Phaneritic
Amorphous, Glassy
Color
Black, Brown, Light to Dark Grey, White
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Durability
Durable
Durable
Appearance
Banded and Foilated
Veined or Pebbled
Interior Uses
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
-
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
-
Other Architectural Uses
Curbing
-
Construction Industry
As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate
for Road Aggregate, Steel Production
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
-
Commercial Uses
Cemetery Markers, Creating Artwork
Electricity Generation
Types
Intermediate intrusive rock
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
Features
Is one of the oldest rock, Typically speckled black and white.
Generally rough to touch, Helps in production of Heat and Electricity, Used as fossil fuel
Archaeological Significance
Formation
When alkali feldspar is extracted from granite, it changes to granitoid and later, it becomes trondhjemite with quartz as major mineral.
Coal formation takes place due to accumulation of plant debris in a swamp environment. The Coal formation process continues, as peat turns into lignite brown or black coal at increasing heat and pressure.
Mineral Content
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
-
Compound Content
NaCl, CaO, MgO, Silicon Dioxide
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
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, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Streak
Bluish Black
Black
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Dull to Vitreous to Submetallic
Specific Gravity
2.86-3
1.1-1.4
Transparency
Opaque
Opaque
Density
2.73 g/cm3
800-801 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
-
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
Africa
Egypt
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Europe
Finland, Germany, Italy, Romania, Sweden, Turkey
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Deposits in Western Continents
North America
USA
Canada, Mexico, USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
Brazil, Chile, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New Zealand, South Australia, Western Australia
New South Wales, Queensland, Victoria