Definition
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
Discoverer
Unknown
Unknown
Etymology
From the locality in Essex County, Massachusetts,US
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Granular
Vesicular
Color
Dark Grey to Black
Black, Brown, Dark Grey to Black, Red
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Banded
Glassy and Vesicular
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Cement Manufacture, Construction Aggregate, for Road Aggregate, In landscaping and drainage works
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
As a traction material on snow-covered roads, Creating Artwork, High-temperature insulation, In gas barbecue grills
Types
Not Available
Not Available
Features
Is one of the oldest rock, Smooth to touch
Available in Lots of Colors and Patterns, Generally rough to touch, Surfaces are often shiny
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
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.
Scoria forms when magma containing huge amount of dissolved gas flows from a volcano during an eruption.
Mineral Content
Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene
Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica
Compound Content
Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
Ca, NaCl
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Highly Porous
Luster
Not Available
Subvitreous to Dull
Cleavage
Not Available
Perfect
Specific Gravity
Not Available
Not Available
Transparency
Opaque
Opaque
Density
Not Available
Not Available
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
Afghanistan, Indonesia, Japan, Russia
Africa
South Africa
Ethiopia, Kenya, Tanzania
Europe
Germany, Greece, Italy, Scotland, Turkey
Greece, Hungary, Iceland, Italy, Turkey
Others
Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA
South America
Brazil, Colombia, Venezuela
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
New Zealand, Queensland
New Zealand, Western Australia