Definition
Rapakivi Granite is a hornblende-biotite Granite containing large rounded crystals of orthoclase which are mantled with oligoclase
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
Origin
Finland, Europe
England
Discoverer
Jakob Sederholm
Abraham Gottlob Werner
Etymology
From Finnish Rapakivi which stands for crumbly rock
From Old French esclate, from esclat (French éclat)
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Granular, Phaneritic
Foliated
Color
Black, Grey, Orange, Pink, White
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Veined or Pebbled
Dull
Interior Uses
Bathrooms, Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings, Paving Stone, Resorts
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
-
Curbing
Construction Industry
As Dimension Stone
As Dimension Stone
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Laboratory bench tops, Tombstones
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
Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite and Hybrid Granite
Phyllite, Schist, and Slate
Features
Available in Lots of Colors and Patterns, It is One of the Oldest, Strongest and Hardest Rock
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Archaeological Significance
Formation
Granite is an igneous rock which is very hard, crystalline and is visibly homogeneous in texture and forms by melting of continental rocks
Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.
Mineral Content
Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Grain Size
Large and Coarse Grained
Very fine-grained
Streak
White
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Dull to Grainy with Sporadic parts Pearly and Vitreous
Dull
Specific Gravity
2.6-2.7
2.65-2.8
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm3
2.6-2.8 g/cm3
Resistance
Heat Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
China, India, Turkey
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
-
Europe
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Deposits in Western Continents
North America
Canada, USA
USA
Deposits in Oceania Continent
All about Rapakivi Granite and Slate Properties
Know all about Rapakivi Granite and Slate properties here. All properties of rocks are important as they define the type of rock and its application. Rapakivi Granite belongs to Igneous Rocks while Slate belongs to Metamorphic Rocks.Texture of Rapakivi Granite is Granular, Phaneritic whereas that of Slate is Foliated. Rapakivi Granite appears Veined or Pebbled and Slate appears Dull. The luster of Rapakivi Granite is dull to grainy with sporadic parts pearly and vitreous while that of Slate is dull. Rapakivi Granite is available in black, grey, orange, pink, white colors whereas Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors. The commercial uses of Rapakivi Granite are cemetery markers, commemorative tablets, creating artwork, curling, laboratory bench tops, tombstones and that 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.