1 Definition
1.1 Definition
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth
1.2 History
1.2.1 Origin
1.2.2 Discoverer
1.3 Etymology
From German Grauwacke, from grau grey + wacke
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
1.4 Class
Sedimentary Rocks
Igneous Rocks
1.4.1 Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
2 Texture
2.1 Texture
2.2 Color
Beige, Black, Brown, Colourless, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
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, Floor Tiles, Flooring, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Garden Decoration
3.1.3 Other Architectural Uses
Curbing, Whetstones
Not Yet Used
3.2 Industry
3.2.1 Construction Industry
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
3.2.2 Medical Industry
3.3 Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Jewellery
3.4 Other Uses
3.4.1 Commercial Uses
As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones
Creating Artwork, Mirror, Used in aquariums
4 Types
4.1 Types
Not Available
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
4.2 Features
Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined
Blocks negativity, Helps to protect against depression
4.3 Archaeological Significance
4.3.1 Monuments
Not Yet Used
Not Yet Used
4.3.2 Famous Monuments
Not Applicable
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
Graywacke rock is a type of sedimentary rock, which is also known as immature sandstone, which is indurated, dark grey and consisting of poorly sorted angular to sub-angular, sand-sized grains.
When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.
5.2 Composition
5.2.1 Mineral Content
Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Not Available
5.2.2 Compound Content
Aluminium Oxide, NaCl, CaO, Chromium(III) Oxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact 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, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Angular and Fine
Not Applicable
6.1.3 Fracture
6.1.4 Streak
6.1.5 Porosity
Highly Porous
Very Less Porous
6.1.6 Luster
6.1.7 Compressive Strength
1.3.3 Cleavage
1.3.4 Toughness
1.3.6 Specific Gravity
1.4.1 Transparency
1.4.2 Density
2.6-2.61 g/cm32.6 g/cm3
0
1400
1.5 Thermal Properties
1.5.1 Specific Heat Capacity
1.5.2 Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
2 Reserves
2.1 Deposits in Eastern Continents
2.1.1 Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Afghanistan, Indonesia, Japan, Russia
2.1.2 Africa
Namibia, Nigeria, South Africa
Kenya
2.1.3 Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Greece, Hungary, Iceland, Italy, Turkey
2.1.4 Others
2.2 Deposits in Western Continents
2.2.1 North America
Canada, USA
Canada, Mexico, USA
2.2.2 South America
Brazil
Argentina, Chile, Ecuador, Peru
2.3 Deposits in Oceania Continent
2.3.1 Australia
New South Wales, New Zealand
New Zealand