Definition
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism
Troctolite is a mafic intrusive rock type. It consists essentially of major but variable amounts of olivine and calcic plagioclase along with minor pyroxene. It is an olivine-rich anorthosite, or a pyroxene-depleted relative of gabbro
Discoverer
Abraham Gottlob Werner
Christian Leopold von Buch
Etymology
From Old French esclate, from esclat (French éclat)
From German Troklotit, from Greek trōktēs, a marine fish (taken to be trout)
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Foliated
Phaneritic
Color
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Dark Grey to Black
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Veined and Shiny
Interior Uses
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Bathrooms, Countertops, Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Jewellery, Monuments, Sculpture
Commercial Uses
Blackboards, Commemorative Tablets, Laboratory bench tops, Standard material for the bed of Billiard table, Standard material for the beds of Pool and Snooker table, Tombstones, Used in aquariums, Writing Slates
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Types
Phyllite, Schist, and Slate
Ultramafic rock
Features
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Smooth to touch
Archaeological Significance
Formation
Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.
Troctolite 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
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Augite, Olivine, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Mechanical Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Very fine-grained
Coarse Grained
Fracture
Splintery
Conchoidal
Streak
Light to dark brown
Black
Porosity
Less Porous
Highly Porous
Specific Gravity
2.65-2.8
2.86-2.87
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm3
2.7-3.3 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Turkey
India, Russia
Europe
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Germany, Greece, Italy, Scotland, Turkey
Deposits in Western Continents
North America
USA
Canada, USA
South America
Brazil
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
-
New Zealand, Queensland
All about Slate and Troctolite Properties
Know all about Slate and Troctolite properties here. All properties of rocks are important as they define the type of rock and its application. Slate belongs to Metamorphic Rocks while Troctolite belongs to Igneous Rocks.Texture of Slate is Foliated whereas that of Troctolite is Phaneritic. Slate appears Dull and Troctolite appears Veined and Shiny. The luster of Slate is dull while that of Troctolite is . Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors whereas Troctolite is available in dark grey to black colors. The commercial uses of Slate are blackboards, commemorative tablets, laboratory bench tops, standard material for the bed of billiard table, standard material for the beds of pool and snooker table, tombstones, used in aquariums, writing slates and that of Troctolite are cemetery markers, commemorative tablets, laboratory bench tops, jewelry, sea defence, tombstones.