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
Rapakivi Granite is a hornblende-biotite Granite containing large rounded crystals of orthoclase which are mantled with oligoclase
Origin
England
Finland, Europe
Discoverer
Unknown
Jakob Sederholm
Etymology
From Old French esclate, from esclat (French éclat)
From Finnish Rapakivi which stands for crumbly rock
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Group
Not Applicable
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Foliated
Granular, Phaneritic
Color
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Black, Grey, Orange, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Veined or Pebbled
Interior Uses
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Bathrooms, Countertops, 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
As Building Stone, As Facing Stone, Office Buildings, Paving Stone, Resorts
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
As Dimension Stone
As Dimension Stone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
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, Creating Artwork, Curling, Laboratory bench tops, Tombstones
Types
Not Available
Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite and Hybrid Granite
Features
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Available in Lots of Colors and Patterns, It is One of the Oldest, Strongest and Hardest Rock
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
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.
Granite is an igneous rock which is very hard, crystalline and is visibly homogeneous in texture and forms by melting of continental rocks
Mineral Content
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
Very fine-grained
Large and Coarse Grained
Fracture
Splintery
Not Available
Streak
Light to dark brown
White
Porosity
Less Porous
Less Porous
Luster
Dull
Dull to Grainy with Sporadic parts Pearly and Vitreous
Cleavage
Slaty
Not Available
Toughness
1.2
Not Available
Specific Gravity
2.65-2.8
2.6-2.7
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm3
2.6-2.8 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Turkey
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
Not Yet Found
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic, Venezuela
Others
Arctic
Not Yet Found
Deposits in Western Continents
North America
USA
Canada, USA
South America
Brazil
Not Yet Found
Deposits in Oceania Continent
Australia
Not Yet Found
Not Yet Found
All about Slate and Rapakivi Granite Properties
Know all about Slate and Rapakivi Granite properties here. All properties of rocks are important as they define the type of rock and its application. Slate belongs to Metamorphic Rocks while Rapakivi Granite belongs to Igneous Rocks.Texture of Slate is Foliated whereas that of Rapakivi Granite is Granular, Phaneritic. Slate appears Dull and Rapakivi Granite appears Veined or Pebbled. The luster of Slate is dull while that of Rapakivi Granite is dull to grainy with sporadic parts pearly and vitreous. Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors whereas Rapakivi Granite is available in black, grey, orange, pink, white 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 Rapakivi Granite are cemetery markers, commemorative tablets, creating artwork, curling, laboratory bench tops, tombstones.