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
History
Origin
England
Discoverer
Abraham Gottlob Werner
Etymology
From Old French esclate, from esclat (French éclat)
Class
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Family
Group
-
Other Categories
Fine Grained Rock, Opaque Rock
Texture
Foliated
Color
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Maintenance
Less
Durability
Durable
Water Resistant
✔
✘
81% - Metamorphic Rocks Rocks have it !
Scratch Resistant
✔
✘
65% - Metamorphic Rocks Rocks have it !
Stain Resistant
✔
✘
42% - Metamorphic Rocks Rocks have it !
Wind Resistant
✔
✘
19% - Metamorphic Rocks Rocks
Acid Resistant
✔
✘
15% - Metamorphic Rocks Rocks
Appearance
Dull
Architecture
Interior Uses
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Industry
Construction Industry
As Dimension Stone
Medical Industry
-
Antiquity Uses
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
Types
Phyllite, Schist, and Slate
Features
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Archaeological Significance
Monuments
-
Famous Monuments
-
Sculpture
-
Famous Sculptures
-
Pictographs
-
Petroglyphs
-
Figurines
-
Fossils
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.
Composition
Mineral Content
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
50% - Metamorphic Rocks Rocks have it !
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Weathering
✔
✘
65% - Metamorphic Rocks Rocks have it !
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
77% - Metamorphic Rocks Rocks have it !
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
3-4
1
7
👆🏻
Grain Size
Very fine-grained
Fracture
Splintery
Streak
Light to dark brown
Porosity
Less Porous
Luster
Dull
Compressive Strength
30.00 N/mm2
Rank: 44 (Overall)
0.15
450
👆🏻
Cleavage
Slaty
Toughness
1.2
Specific Gravity
2.65-2.8
0
8.4
👆🏻
Transparency
Opaque
Density
2.6-2.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.76 kJ/Kg K
Rank: 19 (Overall)
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Turkey
Africa
-
Europe
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Others
Arctic
Deposits in Western Continents
North America
USA
South America
Brazil
Deposits in Oceania Continent
Australia
-