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
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
Discoverer
Unknown
Obsius
Etymology
From Old French esclate, from esclat (French éclat)
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Group
Not Applicable
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
Color
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Interior Uses
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Garden Decoration
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
As Dimension Stone
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
Not Yet Used
Surgery
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Jewellery
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
Creating Artwork, Mirror, Used in aquariums
Types
Not Available
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Features
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Blocks negativity, Helps to protect against depression
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Figurines
Used
Not Yet Used
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.
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.
Mineral Content
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Not Available
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Very fine-grained
Not Applicable
Fracture
Splintery
Conchoidal
Streak
Light to dark brown
White
Porosity
Less Porous
Very Less Porous
Cleavage
Slaty
Non-Existent
Toughness
1.2
Not Available
Specific Gravity
2.65-2.8
2.6-2.7
Transparency
Opaque
Translucent
Density
2.6-2.8 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Turkey
Afghanistan, Indonesia, Japan, Russia
Africa
Not Yet Found
Kenya
Europe
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Greece, Hungary, Iceland, Italy, Turkey
Others
Arctic
Not Yet Found
Deposits in Western Continents
North America
USA
Canada, Mexico, USA
South America
Brazil
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
Not Yet Found
New Zealand
Slate vs Obsidian Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Slate vs Obsidian characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Slate and Properties of Obsidian. Learn more about Slate vs Obsidian in the next section. The interior uses of Slate include Bathrooms, Decorative aggregates, Entryways, Floor tiles, Flooring, Homes, Hotels, Interior decoration, Kitchens and Stair treads whereas the interior uses of Obsidian include Decorative aggregates and Interior decoration. Due to some exceptional properties of Slate and Obsidian, they have various applications in construction industry. The uses of Slate in construction industry include As dimension stone and that of Obsidian include Arrowheads, Cutting tool, Knives, Scrapers, Spear points.
More about Slate and Obsidian
Here you can know more about Slate and Obsidian. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Slate and Obsidian consists of mineral content and compound content. The mineral content of Slate includes Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon and mineral content of Obsidian is not available. You can also check out the list of all Metamorphic Rocks. When we have to compare Slate vs Obsidian, the texture, color and appearance plays an important role in determining the type of rock. Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors whereas, Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. Appearance of Slate is Dull and that of Obsidian is Shiny. Properties of rock is another aspect for Slate vs Obsidian. The hardness of Slate is 3-4 and that of Obsidian is 5-5.5. The types of Slate are Not Available whereas types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Slate is light to dark brown while that of Obsidian is white. The specific heat capacity of Slate is 0.76 kJ/Kg K and that of Obsidian is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Slate is heat resistant, impact resistant, pressure resistant, wear resistant whereas Obsidian is heat resistant, impact resistant.
