Definition
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
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
Origin
Indonesia
Ethiopia
Discoverer
Cornish Gossen
Obsius
Etymology
From Cornish gossen from gos, blood from Old Cornish guit
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, Medium Grained Rock, Opaque Rock
Opaque Rock
Texture
Rough, Sandy
Glassy
Color
Brown, Brown- Black, Gold, Green, Rust
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Banded
Shiny
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Garden Decoration
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
Not Yet Used
Surgery
Antiquity Uses
Artifacts
Artifacts, Jewellery
Commercial Uses
Cemetery Markers, Commemorative Tablets, Gemstone
Creating Artwork, Mirror, Used in aquariums
Types
Translocated gossan and Leakage gossan
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
Features
Clasts are smooth to touch, Easily splits into thin plates
Blocks negativity, Helps to protect against depression
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Not Applicable
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Figurines
Not Yet Used
Not Yet Used
Formation
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
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, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
Not Available
Compound Content
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine to Medium Grained
Not Applicable
Fracture
Conchoidal
Conchoidal
Streak
White to Grey
White
Porosity
Highly Porous
Very Less Porous
Compressive Strength
Not Available
Cleavage
Not Available
Non-Existent
Toughness
Not Available
Not Available
Specific Gravity
2.0
2.6-2.7
Transparency
Opaque
Translucent
Density
Not Available
2.6 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Russia, Singapore, South Korea
Afghanistan, Indonesia, Japan, Russia
Africa
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
Kenya
Europe
Albania, France, Germany, Great Britain, United Kingdom
Greece, Hungary, Iceland, Italy, Turkey
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Brazil, Colombia, Ecuador
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
New South Wales, South Australia, Western Australia
New Zealand
Gossan 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. Gossan vs Obsidian characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gossan and Properties of Obsidian. Learn more about Gossan vs Obsidian in the next section. The interior uses of Gossan include Countertops, Decorative aggregates and Interior decoration whereas the interior uses of Obsidian include Decorative aggregates and Interior decoration. Due to some exceptional properties of Gossan and Obsidian, they have various applications in construction industry. The uses of Gossan in construction industry include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate and that of Obsidian include Arrowheads, Cutting tool, Knives, Scrapers, Spear points.
More about Gossan and Obsidian
Here you can know more about Gossan and Obsidian. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gossan and Obsidian consists of mineral content and compound content. The mineral content of Gossan includes Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, 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 Gossan vs Obsidian, the texture, color and appearance plays an important role in determining the type of rock. Gossan is available in brown, brown- black, gold, green, rust colors whereas, Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. Appearance of Gossan is Dull and Banded and that of Obsidian is Shiny. Properties of rock is another aspect for Gossan vs Obsidian. The hardness of Gossan is 4-5 and that of Obsidian is 5-5.5. The types of Gossan are Translocated gossan and Leakage gossan 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 Gossan is white to grey while that of Obsidian is white. The specific heat capacity of Gossan is 0.24 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.Gossan is heat resistant, impact resistant, pressure resistant whereas Obsidian is heat resistant, impact resistant.