Definition
Rapakivi Granite is a hornblende-biotite Granite containing large rounded crystals of orthoclase which are mantled with oligoclase
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
Origin
Finland, Europe
Iceland
Discoverer
Jakob Sederholm
Unknown
Etymology
From Finnish Rapakivi which stands for crumbly rock
From German Tachylite, from tachy- + Greek lutos soluble, melting
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Granular, Phaneritic
Vitreous
Color
Black, Grey, Orange, Pink, White
Black, Dark Brown
Durability
Durable
Durable
Appearance
Veined or Pebbled
Glassy
Interior Uses
Bathrooms, Countertops, 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, Office Buildings, Paving Stone, Resorts
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
-
Curbing
Construction Industry
As Dimension Stone
Cutting Tool, Knives, Landscaping, Scrapers
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Laboratory bench tops, Tombstones
Cemetery Markers, Creating Artwork
Types
Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite and Hybrid Granite
Volcanic glass
Features
Available in Lots of Colors and Patterns, It is One of the Oldest, Strongest and Hardest Rock
Available in Lots of Colors and Patterns, Clasts are smooth to touch
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
Tachylite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Feldspar, Olivine
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Fe, Mg
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact 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
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Large and Coarse Grained
Medium to Fine Coarse Grained
Porosity
Less Porous
Less Porous
Luster
Dull to Grainy with Sporadic parts Pearly and Vitreous
Resinous
Specific Gravity
2.6-2.7
2.4
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm3
3.058 g/cm3
Resistance
Heat Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Cambodia, Russia, South Korea
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
East Africa
Europe
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic
England, Germany, Hungary, Iceland, Scotland, Sweden
Deposits in Western Continents
North America
Canada, USA
USA
Deposits in Oceania Continent
Rapakivi Granite vs Tachylite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Rapakivi Granite vs Tachylite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Rapakivi Granite and Properties of Tachylite. Learn more about Rapakivi Granite vs Tachylite in the next section. The interior uses of Rapakivi Granite include Bathrooms, Countertops, Decorative aggregates, Entryways, Floor tiles, Flooring, Homes, Hotels, Interior decoration, Kitchens and Stair treads whereas the interior uses of Tachylite include Decorative aggregates and Interior decoration. Due to some exceptional properties of Rapakivi Granite and Tachylite, they have various applications in construction industry. The uses of Rapakivi Granite in construction industry include As dimension stone and that of Tachylite include Cutting tool, Knives, Landscaping, Scrapers.
More about Rapakivi Granite and Tachylite
Here you can know more about Rapakivi Granite and Tachylite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Rapakivi Granite and Tachylite consists of mineral content and compound content. The mineral content of Rapakivi Granite includes Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz and mineral content of Tachylite includes Feldspar, Olivine. You can also check out the list of all Igneous Rocks. When we have to compare Rapakivi Granite vs Tachylite, the texture, color and appearance plays an important role in determining the type of rock. Rapakivi Granite is available in black, grey, orange, pink, white colors whereas, Tachylite is available in black, dark brown colors. Appearance of Rapakivi Granite is Veined or Pebbled and that of Tachylite is Glassy. Properties of rock is another aspect for Rapakivi Granite vs Tachylite. The hardness of Rapakivi Granite is 6-7 and that of Tachylite is 5.5. The types of Rapakivi Granite are Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite and Hybrid Granite whereas types of Tachylite are Volcanic glass. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Rapakivi Granite is white while that of Tachylite is vermilion. The specific heat capacity of Rapakivi Granite is 0.79 kJ/Kg K and that of Tachylite is 0.56 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Rapakivi Granite is heat resistant, wear resistant whereas Tachylite is heat resistant, impact resistant, wear resistant.