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.
  
Pumice is a volcanic rock that consists of highly vesicular rough textured volcanic glass, which may or may not contain crystals
  
History
  
  
Origin
Tonale, Italy
  
Spain
  
Discoverer
Unknown
  
Unknown
  
Etymology
Not Available
  
From Old French pomis, from a Latin dialect variant of pumex
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Plutonic
  
Volcanic
  
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Phaneritic
  
Vesicular
  
Color
Black, Brown, Light to Dark Grey, White
  
Beige, Colourless, Grey, Light Green, Light Grey, Pink, White, Yellow- grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
No
  
No
  
Acid Resistant
No
  
Yes
  
Appearance
Banded and Foilated
  
Vesicular
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
  
Decorative Aggregates, Flooring, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
  
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing, Powder
  
Industry
  
  
Construction Industry
As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate
  
As Dimension Stone, Cement Manufacture, for Road Aggregate, In landscaping and horticulture, Making natural cement, Production of lightweight concrete blocks
  
Medical Industry
Not Yet Used
  
As an abrasive in skin exfoliating products, In Chemical and Pharmaceutical Industry, Medicines and Cosmetics
  
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
  
Artifacts
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Creating Artwork
  
As a traction material on snow-covered roads, As an abrasive in pencil erasers, Fine abrasive used for polishing, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Used in aquariums
  
Types
Not Available
  
Scoria
  
Features
Is one of the oldest rock, Typically speckled black and white.
  
Host Rock for Lead
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Not Yet Used
  
Famous Monuments
Not Applicable
  
Not Applicable
  
Sculpture
Used
  
Not Yet Used
  
Famous Sculptures
Data Not Available
  
Not Applicable
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Not Yet Used
  
Fossils
Absent
  
Absent
  
Formation
When alkali feldspar is extracted from granite, it changes to granitoid and later, it becomes trondhjemite with quartz as major mineral.
  
Pumice rock forms when the magma cools so quickly that atoms in the melt are not able to arrange themselves into a crystalline structure.
  
Composition
  
  
Mineral Content
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
  
Aluminum Oxides, Calcite, Carbonate, Iron Oxides, Silica
  
Compound Content
NaCl, CaO, MgO, Silicon Dioxide
  
Al, Aluminium Oxide, CaO, Carbon Dioxide, MgO, Silicon Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Burial Metamorphism, Impact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
6-7
  
6
  
Grain Size
Medium to Fine Coarse Grained
  
Fine Grained
  
Fracture
Conchoidal
  
Planar
  
Streak
Bluish Black
  
White, Greenish White or Grey
  
Porosity
Very Less Porous
  
Highly Porous
  
Luster
Subvitreous to Dull
  
Earthy
  
Compressive Strength
Not Available
  
51.20 N/mm
2
  
26
Cleavage
Not Available
  
Perfect
  
Toughness
2.1
  
3
  
Specific Gravity
2.86-3
  
2.86
  
Transparency
Opaque
  
Opaque
  
Density
2.73 g/cm3
  
0.25-0.3 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.92 kJ/Kg K
  
10
0.87 kJ/Kg K
  
14
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
  
Impact Resistant, Pressure Resistant
  
Deposits in Eastern Continents
  
  
Asia
Not Yet Found
  
Afghanistan, Indonesia, Japan, Russia
  
Africa
Egypt
  
Ethiopia, Kenya, Tanzania
  
Europe
Finland, Germany, Italy, Romania, Sweden, Turkey
  
Greece, Hungary, Iceland, Italy, Turkey
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
USA
  
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA
  
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
  
Argentina, Chile, Ecuador, Peru
  
Deposits in Oceania Continent
  
  
Australia
New Zealand, South Australia, Western Australia
  
New Zealand, Western Australia