Definition
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
  
Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock
  
History
  
  
Origin
USA
  
New Zealand
  
Discoverer
Unknown
  
Unknown
  
Etymology
From the locality in Essex County, Massachusetts,US
  
From German which means hornstone
  
Class
Igneous Rocks
  
Metamorphic Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Soft Rock
  
Family
  
  
Group
Plutonic
  
Not Applicable
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Granular
  
Granular, Platy
  
Color
Dark Grey to Black
  
Brown, Dark Greenish - Grey, Green, Reddish Brown
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
No
  
Stain Resistant
Yes
  
No
  
Wind Resistant
Yes
  
No
  
Acid Resistant
No
  
No
  
Appearance
Banded
  
Dull
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
  
Decorative Aggregates, Flooring, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
for Road Aggregate, Roadstone
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
  
Artifacts, Monuments
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
  
Cemetery Markers, Commemorative Tablets, Creating Artwork
  
Types
Not Available
  
Biotite hornfels
  
Features
Is one of the oldest rock, Smooth to touch
  
Smooth to touch
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Used
  
Not Yet Used
  
Famous Sculptures
Data Not Available
  
Not Applicable
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Not Yet Used
  
Fossils
Absent
  
Absent
  
Formation
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.
  
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
  
Composition
  
  
Mineral Content
Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene
  
Andalusite
  
Compound Content
Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
  
Fe, Mg
  
Transformation
  
  
Metamorphism
Yes
  
No
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering
  
Biological Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
  
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
7
  
2-3
  
Grain Size
Fine Grained
  
Fine Grained
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
Black
  
Unknown
  
Porosity
Highly Porous
  
Highly Porous
  
Luster
Not Available
  
Shiny
  
Compressive Strength
Not Available
  
Cleavage
Not Available
  
Perfect
  
Toughness
1.6
  
Not Yet Found
  
Specific Gravity
Not Available
  
3.4-3.9
  
Transparency
Opaque
  
Opaque
  
Density
Not Available
  
0.25-0.30 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.84 kJ/Kg K
  
15
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Impact Resistant, Pressure Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
  
Africa
South Africa
  
Cameroon, East Africa, Tanzania, Western Africa
  
Europe
Germany, Greece, Italy, Scotland, Turkey
  
United Kingdom
  
Others
Greenland
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil, Colombia, Venezuela
  
Bolivia, Brazil, Colombia, Ecuador
  
Deposits in Oceania Continent
  
  
Australia
New Zealand, Queensland
  
New South Wales, New Zealand, Queensland, Western Australia
  
Essexite vs Hornfels 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. Essexite vs Hornfels characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Essexite and Properties of Hornfels. Learn more about Essexite vs Hornfels in the next section. The interior uses of Essexite include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Essexite and Hornfels, they have various applications in construction industry. The uses of Essexite in construction industry include As dimension stone, Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate and that of Hornfels include For road aggregate, Roadstone.
More about Essexite and Hornfels
Here you can know more about Essexite and Hornfels. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Essexite and Hornfels consists of mineral content and compound content. The mineral content of Essexite includes Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene and mineral content of Hornfels includes Andalusite. You can also check out the list of all Igneous Rocks. When we have to compare Essexite vs Hornfels, the texture, color and appearance plays an important role in determining the type of rock. Essexite is available in dark grey to black colors whereas, Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. Appearance of Essexite is Banded and that of Hornfels is Dull. Properties of rock is another aspect for Essexite vs Hornfels. The hardness of Essexite is 7 and that of Hornfels is 2-3. The types of Essexite are Not Available whereas types of Hornfels are Biotite hornfels. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Essexite is black while that of Hornfels is unknown. The specific heat capacity of Essexite is Not Available and that of Hornfels is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Essexite is impact resistant, pressure resistant, wear resistant whereas Hornfels is heat resistant, impact resistant, pressure resistant.