1 Definition
1.1 Definition
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
1.2 History
1.2.1 Origin
USA
Romania and Moldova, Europe
1.2.2 Discoverer
1.3 Etymology
From the locality in Essex County, Massachusetts,US
From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described
1.4 Class
Igneous Rocks
Igneous Rocks
1.4.1 Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
2 Texture
2.1 Texture
Granular
Aphanitic to Porphyritic
2.2 Color
Dark Grey to Black
Bluish - Grey, Brown, Grey, Light to Dark Grey
2.3 Maintenance
2.4 Durability
2.4.1 Water Resistant
2.4.2 Scratch Resistant
2.4.3 Stain Resistant
2.4.4 Wind Resistant
2.4.5 Acid Resistant
2.5 Appearance
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Entryways, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, Paving Stone, Garden Decoration
3.1.3 Other Architectural Uses
3.2 Industry
3.2.1 Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
3.2.2 Medical Industry
Not Yet Used
Not Yet Used
3.3 Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
3.4 Other Uses
3.4.1 Commercial Uses
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
Commemorative Tablets, Creating Artwork
4 Types
4.1 Types
Not Available
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
4.2 Features
Is one of the oldest rock, Smooth to touch
Host Rock for Lead, Is one of the oldest rock
4.3 Archaeological Significance
4.3.1 Monuments
4.3.2 Famous Monuments
Data Not Available
Not Applicable
4.3.3 Sculpture
4.3.4 Famous Sculptures
Data Not Available
Not Applicable
4.3.5 Pictographs
4.3.6 Petroglyphs
4.3.7 Figurines
4.4 Fossils
5 Formation
5.1 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.
Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.
5.2 Composition
5.2.1 Mineral Content
Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
5.2.2 Compound Content
Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
5.3.3 Weathering
5.3.4 Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
5.3.5 Erosion
5.3.6 Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Chemical Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Fine Grained
Medium to Fine Coarse Grained
6.1.3 Fracture
6.1.4 Streak
6.1.5 Porosity
Highly Porous
Less Porous
6.1.6 Luster
Not Available
Subvitreous to Dull
6.1.7 Compressive Strength
6.1.8 Cleavage
6.1.9 Toughness
6.1.10 Specific Gravity
Not Available2.86-2.87
0
8.4
6.1.11 Transparency
6.1.12 Density
Not Available2.77-2.771 g/cm3
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
6.2.2 Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
India, Russia
Not Yet Found
7.1.2 Africa
South Africa
Not Yet Found
7.1.3 Europe
Germany, Greece, Italy, Scotland, Turkey
France, Greece, Romania, Scotland, Spain
7.1.4 Others
7.2 Deposits in Western Continents
7.2.1 North America
7.2.2 South America
Brazil, Colombia, Venezuela
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
7.3 Deposits in Oceania Continent
7.3.1 Australia
New Zealand, Queensland
New Zealand, South Australia, Western Australia