Definition
Amphibolite can be defined as a granular metamorphic rock which mainly consist of hornblende and plagioclase
  
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
  
History
  
  
Origin
Unknown
  
USA
  
Discoverer
Alexandre Brongniart
  
Unknown
  
Etymology
From Amphibole + -ite
  
From the locality in Essex County, Massachusetts,US
  
Class
Metamorphic Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Plutonic
  
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Banded, Foliated, Massive
  
Granular
  
Color
Black, Brown, Green, Grey
  
Dark Grey to Black
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
No
  
Yes
  
Acid Resistant
Yes
  
No
  
Appearance
Foliated
  
Banded
  
Architecture
  
  
Interior Uses
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Kitchens
  
Decorative Aggregates, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
  
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, Cobblestones, Construction Aggregate, for Road Aggregate, Landscaping, Production of Glass and Ceramics, Roadstone
  
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, Sculpture, Small Figurines
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
  
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
  
Types
Hornblendite
  
Not Available
  
Features
Clasts are smooth to touch, Matrix variable, Surfaces are often shiny
  
Is one of the oldest rock, Smooth to touch
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Not Used
  
Not Used
  
Petroglyphs
Not Used
  
Not Used
  
Figurines
Used
  
Used
  
Fossils
Absent
  
Absent
  
Formation
Amphibolite is a coarse-grained metamorphic rock which forms by metamorphism of mafic igneous rocks like basalt and gabbro or from the metamorphism of clay-rich sedimentary rocks like marl or graywacke.
  
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.
  
Composition
  
  
Mineral Content
Amphibole, Andalusite, Biotite, Calcite, Epidote, Garnet, Hornblade, Kyanite, Magnetite, Olivine, Plagioclase, Pyroxene, Staurolite, Wollastonite
  
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
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Wind Erosion
  
Coastal Erosion, Glacier Erosion, Water Erosion
  
Physical Properties
  
  
Hardness
6-7
  
7
  
Grain Size
Medium to Coarse Grained
  
Fine Grained
  
Fracture
Irregular to Conchoidal
  
Conchoidal
  
Streak
White to Grey
  
Black
  
Porosity
Less Porous
  
Highly Porous
  
Luster
Vitreous to Dull
  
Not Available
  
Cleavage
Irregular
  
Not Available
  
Toughness
2.3
  
1.6
  
Specific Gravity
2.5
  
Not Available
  
Transparency
Opaque
  
Opaque
  
Density
2.85-3.07 g/cm3
  
Not Available
  
Thermal Properties
  
  
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
  
Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
Russia, Turkey
  
India, Russia
  
Africa
Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda
  
South Africa
  
Europe
Germany, Greece, Iceland, Norway, Poland
  
Germany, Greece, Italy, Scotland, Turkey
  
Others
Not Yet Found
  
Greenland
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil
  
Brazil, Colombia, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
South Australia, Western Australia
  
New Zealand, Queensland