Definition
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
Gabbro is an intrusive igneous rock which is chemically equivalent to plutonic Basalt
Origin
New Zealand
Germany
Discoverer
Unknown
Christian Leopold von Buch
Etymology
From German which means hornstone
From Latin glaber bare, smooth, bald
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Granular, Platy
Phaneritic
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Dark Grey to Black
Durability
Durable
Durable
Appearance
Dull
Veined and Shiny
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, 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
Construction Industry
for Road Aggregate, Roadstone
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Types
Biotite hornfels
Anorthosite Gabbro and Norite Gabbro
Features
Smooth to touch
Smooth to touch
Archaeological Significance
Formation
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.
Gabbro, a mafic rock, forms due to cooling and crystallization of magma underneath Earth's surface.
Mineral Content
Andalusite
Augite, Olivine, Plagioclase, Pyroxene
Compound Content
Fe, Mg
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Types of Metamorphism
-
Impact Metamorphism
Types of Weathering
Biological Weathering
Chemical Weathering
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Coastal Erosion
Grain Size
Fine Grained
Coarse Grained
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Highly Porous
Specific Gravity
3.4-3.9
2.86-2.87
Transparency
Opaque
Opaque
Density
0.25-0.30 g/cm3
2.7-3.3 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
India, Russia
Africa
Cameroon, East Africa, Tanzania, Western Africa
South Africa
Europe
United Kingdom
Germany, Greece, Italy, Scotland, Turkey
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Bolivia, Brazil, Colombia, Ecuador
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
New Zealand, Queensland
Hornfels vs Gabbro 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. Hornfels vs Gabbro characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Hornfels and Properties of Gabbro. Learn more about Hornfels vs Gabbro in the next section. The interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration whereas the interior uses of Gabbro include Countertops, Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Hornfels and Gabbro, they have various applications in construction industry. The uses of Hornfels in construction industry include For road aggregate, Roadstone and that of Gabbro include As dimension stone, Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate.
More about Hornfels and Gabbro
Here you can know more about Hornfels and Gabbro. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Hornfels and Gabbro consists of mineral content and compound content. The mineral content of Hornfels includes Andalusite and mineral content of Gabbro includes Augite, Olivine, Plagioclase, Pyroxene. You can also check out the list of all Metamorphic Rocks. When we have to compare Hornfels vs Gabbro, the texture, color and appearance plays an important role in determining the type of rock. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas, Gabbro is available in dark grey to black colors. Appearance of Hornfels is Dull and that of Gabbro is Veined and Shiny. Properties of rock is another aspect for Hornfels vs Gabbro. The hardness of Hornfels is 2-3 and that of Gabbro is 7. The types of Hornfels are Biotite hornfels whereas types of Gabbro are Anorthosite Gabbro and Norite Gabbro. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Hornfels is while that of Gabbro is black. The specific heat capacity of Hornfels is 0.84 kJ/Kg K and that of Gabbro is 0.71 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Hornfels is heat resistant, impact resistant, pressure resistant whereas Gabbro is impact resistant, pressure resistant, wear resistant.