Definition
Rapakivi Granite is a hornblende-biotite Granite containing large rounded crystals of orthoclase which are mantled with oligoclase
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
Origin
Finland, Europe
USA
Discoverer
Jakob Sederholm
Unknown
Etymology
From Finnish Rapakivi which stands for crumbly rock
From the locality in Essex County, Massachusetts,US
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Granular, Phaneritic
Granular
Color
Black, Grey, Orange, Pink, White
Dark Grey to Black
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Veined or Pebbled
Banded
Interior Uses
Bathrooms, Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings, Paving Stone, Resorts
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Not Yet Used
Curbing
Construction Industry
As Dimension Stone
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
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
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
Types
Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite and Hybrid Granite
Not Available
Features
Available in Lots of Colors and Patterns, It is One of the Oldest, Strongest and Hardest Rock
Is one of the oldest rock, Smooth to touch
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Formation
Granite is an igneous rock which is very hard, crystalline and is visibly homogeneous in texture and forms by melting of continental rocks
Essexite is a type of igneous rock, which is usually dark grey to black plutonic rock. For the formation of essexite, suitable magma with exact composition of K, Ba, Rb, Cs, Sr should be produced.
Mineral Content
Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Grain Size
Large and Coarse Grained
Fine Grained
Fracture
Not Available
Conchoidal
Porosity
Less Porous
Highly Porous
Luster
Dull to Grainy with Sporadic parts Pearly and Vitreous
Not Available
Compressive Strength
Not Available
Cleavage
Not Available
Not Available
Toughness
Not Available
1.6
Specific Gravity
2.6-2.7
Not Available
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm3
Not Available
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Wear Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
India, Russia
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
South Africa
Europe
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic, Venezuela
Germany, Greece, Italy, Scotland, Turkey
Others
Not Yet Found
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Not Yet Found
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
Not Yet Found
New Zealand, Queensland