Definition
Amphibolite can be defined as a granular metamorphic rock which mainly consist of hornblende and plagioclase
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
History
Origin
-
-
Discoverer
Alexandre Brongniart
Unknown
Etymology
From Amphibole + -ite
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
-
-
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Banded, Foliated, Massive
Banded, Rough
Color
Black, Brown, Green, Grey
Black, Brown, Green, Grey, Red, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Foliated
Glassy or Pearly
Architecture
Interior Uses
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Kitchens
Decorative Aggregates, Homes
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
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
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Medical Industry
-
-
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Monuments
Other Uses
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Types
Hornblendite
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Features
Clasts are smooth to touch, Matrix variable, Surfaces are often shiny
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
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.
Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.
Composition
Mineral Content
Amphibole, Andalusite, Biotite, Calcite, Epidote, Garnet, Hornblade, Kyanite, Magnetite, Olivine, Plagioclase, Pyroxene, Staurolite, Wollastonite
Quartz, Silicon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
-
Weathering
✔
✘
✔
✘
Types of Weathering
Chemical Weathering, Mechanical Weathering
-
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Wind Erosion
Chemical Erosion
Physical Properties
Hardness
6-76.5-7
1
7
👆🏻
Grain Size
Medium to Coarse Grained
Very fine-grained
Fracture
Irregular to Conchoidal
Uneven, Splintery or Conchoidal
Streak
White to Grey
White
Porosity
Less Porous
Highly Porous
Luster
Vitreous to Dull
Waxy and Dull
Compressive Strength
90.00 N/mm2450.00 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
2.3
1.5
Specific Gravity
2.52.5-2.8
0
8.4
👆🏻
Transparency
Opaque
Translucent to Opaque
Density
2.85-3.07 g/cm32.7 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K0.74 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Russia, Turkey
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda
Kenya, Morocco, South Africa, Tanzania
Europe
Germany, Greece, Iceland, Norway, Poland
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
-
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Brazil
Bolivia, Brazil
Deposits in Oceania Continent
Australia
South Australia, Western Australia
New South Wales, Queensland, South Australia, Western Australia