Definition
Siltstone can be defined as a fine-grained sedimentary rock which mainly consists of consolidated silt
Shoshonite is a basaltic rock, properly a potassic trachyandesite, composed of olivine, augite and plagioclase phenocrysts in a groundmass with calcic plagioclase and sanidine and some dark-colored volcanic glass
Discoverer
Unknown
Iddings
Etymology
From English word silt and stone and from Proto-Indo-European root sal and stainaz
From the place of origin called Shoshone riverin Wyoming
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Clastic
Porphyritic
Color
Brown, Red, Reddish Brown
Brown- Black, Dark Brown
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Sculpture
Commercial Uses
Raw material for the manufacture of mortar, Soil Conditioner
Cemetery Markers, Creating Artwork
Types
Siltstone
Intermediate volcanic rock
Features
Available in Lots of Colors and Patterns, Easily splits into thin plates, Generally rough to touch, High silica content, Very fine grained rock
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Formation
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.
Shoshonite 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.
Mineral Content
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz, Sand, Silica, Silt
Pyroxene
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
Aluminium Oxide, Iron(III) Oxide, Potassium Oxide, Sodium Oxide, Titanium Dioxide
Types of Metamorphism
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Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Uneven
Streak
White
White to Grey
Porosity
Highly Porous
Less Porous
Specific Gravity
2.54-2.73
2.98
Transparency
Opaque
Opaque
Density
2.6-2.7 g/cm3
2.9-3 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Water Resistant
Heat Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
India, Russia
Africa
Namibia, Nigeria, South Africa
South Africa
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Iceland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand
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