Definition
Diabase is a fine-grained igneous rock which is composed mostly of pyroxene and feldspar
Siltstone can be defined as a fine-grained sedimentary rock which mainly consists of consolidated silt
Discoverer
Christian Leopold von Buch
Unknown
Etymology
From Greek di + base
From English word silt and stone and from Proto-Indo-European root sal and stainaz
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic, Granular
Clastic
Color
Dark Grey to Black
Brown, Red, Reddish Brown
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Vesicular
Rough
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration, Kitchens
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Sculpture, Small Figurines
Commercial Uses
An Oil and Gas Reservoir, Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Raw material for the manufacture of mortar, Soil Conditioner
Features
Smooth to touch
Available in Lots of Colors and Patterns, Easily splits into thin plates, Generally rough to touch, High silica content, Very fine grained rock
Archaeological Significance
Famous Monuments
Stonehenge in English county of Wiltshire
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Formation
Diabase forms when molten igneous rock is squeezed up into a vertical crack in other rocks, the crack is usually forced apart and the molten rock cools in the space to form a tabular igneous intrusion cutting across the surrounding rocks and is known as a dike.
Siltstone is a type of sedimentary rock which is formed from fine rock particles. As the particles of eroded rock travel along with water, the edges of the rock are worn-out by water into a rounded shape.
Mineral Content
Augite, Chlorite, Olivine, Plagioclase, Pyroxene, Pyrrhotite, Serpentine
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz, Sand, Silica, Silt
Compound Content
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
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Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine to Medium Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Highly Porous
Specific Gravity
2.86-2.87
2.54-2.73
Transparency
Opaque
Opaque
Density
2.7-3.3 g/cm3
2.6-2.7 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Water Resistant
Deposits in Eastern Continents
Asia
India
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
South Africa, Tanzania
Namibia, Nigeria, South Africa
Europe
Germany, Greece, Italy, Scotland, Turkey
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Others
Antarctica, Greenland
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Argentina, Brazil, Colombia, Venezuela
Brazil
Deposits in Oceania Continent
Australia
Central Australia, New Zealand, Queensland, Western Australia
New South Wales, New Zealand