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
Diorite is a grey to dark-grey intermediate intrusive igneous rock composed principally of plagioclase feldspar,biotite, hornblende, and pyroxene
History
Origin
England
-
Discoverer
Abraham Gottlob Werner
Unknown
Etymology
From Old French esclate, from esclat (French éclat)
From early 19th century coined in French, formed irregularly from Greek diorizein distinguish
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
-
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Foliated
Phaneritic
Color
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Black, Brown, Light to Dark Grey, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull
Shiny
Architecture
Interior Uses
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone
As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
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
Creating Artwork, Curling
Types
Phyllite, Schist, and Slate
Plagioclase Diorite and Quartz Diorite
Features
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Typically speckled black and white.
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
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.
Diorite is a coarse-grained intrusive igneous rock which contains large interlocking and randomly oriented crystals and forms when molten lava does not reach the Earth’s surface and cools down in the Earth’s crust.
Composition
Mineral Content
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Muscovite or Illite, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Physical Properties
Hardness
3-46-7
1
7
👆🏻
Grain Size
Very fine-grained
Medium to Coarse Grained
Fracture
Splintery
-
Streak
Light to dark brown
Bluish Black
Porosity
Less Porous
Very Less Porous
Luster
Dull
Shiny
Compressive Strength
30.00 N/mm2225.00 N/mm2
0.15
450
👆🏻
Cleavage
Slaty
-
Toughness
1.2
2.1
Specific Gravity
2.65-2.82.8-3
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm32.8-3 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.76 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Turkey
-
Africa
-
Egypt
Europe
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Finland, Germany, Italy, Romania, Sweden, Turkey, United Kingdom
Others
Arctic
-
Deposits in Western Continents
North America
USA
USA
South America
Brazil
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
Deposits in Oceania Continent
Australia
-
New Zealand, Western Australia