Definition
Hornblendite is a type of igneous plutonic rock consisting mainly of amphibole hornblende and is a type of Amphibolite rock
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks
Discoverer
Unknown
Unknown
Etymology
From German, Horn horn + blende
From the Middle High German verb gneist (to spark; so called because the rock glitters)
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Plutonic
Not Applicable
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Banded, Foliated, Massive
Banded, Foliated, Platy
Color
Black, Brown, Green, Grey
Black, Brown, Pink, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Foliated
Foliated
Interior Uses
Countertops, Decorative Aggregates, Entryways, Flooring, Homes, Hotels, Interior Decoration, Kitchens
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
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
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Types
Hornblende Gabbro and Hornblende Peridotite
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Features
Clasts are smooth to touch, Matrix variable, Surfaces are often shiny
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Konark Sun Temple in India, Washington Monument, US
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Used
Not Yet Used
Formation
Hornblendite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.
Mineral Content
Amphibole, Calcite, Hornblade, Magnetite, Plagioclase, Wollastonite
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Not Applicable
Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
Grain Size
Medium to Coarse Grained
Medium to Coarse Grained
Fracture
Irregular to Conchoidal
Irregular
Streak
White to Grey
White
Porosity
Less Porous
Very Less Porous
Luster
Vitreous to Dull
Dull
Compressive Strength
Not Available
Specific Gravity
2.5
2.5-2.7
Transparency
Opaque
Translucent to Opaque
Density
2.85-3.07 g/cm3
2.6-2.9 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Russia, Turkey
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
Africa
Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Europe
Germany, Greece, Iceland, Norway, Poland
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Brazil
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
South Australia, Western Australia
New South Wales, New Zealand, Queensland, Victoria