Definition
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism
  
Gabbro is an intrusive igneous rock which is chemically equivalent to plutonic Basalt
  
History
  
  
Origin
England
  
Germany
  
Discoverer
Unknown
  
Christian Leopold von Buch
  
Etymology
From Old French esclate, from esclat (French éclat)
  
From Latin glaber bare, smooth, bald
  
Class
Metamorphic Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Plutonic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Coarse Grained Rock, Opaque Rock
  
Texture
Foliated
  
Phaneritic
  
Color
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
  
Dark Grey to Black
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
No
  
Yes
  
Acid Resistant
No
  
Yes
  
Appearance
Dull
  
Veined and Shiny
  
Architecture
  
  
Interior Uses
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
  
Countertops, Decorative Aggregates, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
  
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone
  
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
Blackboards, Commemorative Tablets, Laboratory bench tops, Standard material for the bed of Billiard table, Standard material for the beds of Pool and Snooker table, Tombstones, Used in aquariums, Writing Slates
  
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
  
Types
Not Available
  
Not Available
  
Features
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
  
Smooth to touch
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Used
  
Not Used
  
Petroglyphs
Used
  
Not Used
  
Figurines
Used
  
Used
  
Fossils
Absent
  
Absent
  
Formation
Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.
  
Gabbro, a mafic rock, forms due to cooling and crystallization of magma underneath Earth's surface.
  
Composition
  
  
Mineral Content
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
  
Augite, Olivine, Plagioclase, Pyroxene
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
  
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
  
Impact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Chemical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
  
Coastal Erosion
  
Physical Properties
  
  
Hardness
3-4
  
7
  
Grain Size
Very fine-grained
  
Coarse Grained
  
Fracture
Splintery
  
Conchoidal
  
Streak
Light to dark brown
  
Black
  
Porosity
Less Porous
  
Highly Porous
  
Luster
Dull
  
Not Available
  
Compressive Strength
30.00 N/mm2
  
30
225.00 N/mm2
  
7
Cleavage
Slaty
  
Not Available
  
Toughness
1.2
  
1.6
  
Specific Gravity
2.65-2.8
  
2.86-2.87
  
Transparency
Opaque
  
Opaque
  
Density
2.6-2.8 g/cm3
  
2.7-3.3 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.76 kJ/Kg K
  
17
Not Available
  
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
  
Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Turkey
  
India, Russia
  
Africa
Not Yet Found
  
South Africa
  
Europe
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
  
Germany, Greece, Italy, Scotland, Turkey
  
Others
Arctic
  
Greenland
  
Deposits in Western Continents
  
  
North America
USA
  
Canada, USA
  
South America
Brazil
  
Brazil, Colombia, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
New Zealand, Queensland
  
All about Slate and Gabbro Properties
Know all about Slate and Gabbro properties here. All properties of rocks are important as they define the type of rock and its application. Slate belongs to Metamorphic Rocks while Gabbro belongs to Igneous Rocks.Texture of Slate is Foliated whereas that of Gabbro is Phaneritic. Slate appears Dull and Gabbro appears Veined and Shiny. The luster of Slate is dull while that of Gabbro is not available. Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors whereas Gabbro is available in dark grey to black colors. The commercial uses of Slate are blackboards, commemorative tablets, laboratory bench tops, standard material for the bed of billiard table, standard material for the beds of pool and snooker table, tombstones, used in aquariums, writing slates and that of Gabbro are cemetery markers, commemorative tablets, laboratory bench tops, jewelry, sea defence, tombstones.