Definition
Rhyolite is a fine-grained igneous rock which is rich in silica
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
Origin
North America
Indonesia
Discoverer
Ferdinand von Richthofen
Cornish Gossen
Etymology
From German Rhyolit, from Greek rhuax lava stream + lithos stone
From Cornish gossen from gos, blood from Old Cornish guit
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Aphanitic, Glassy, Porphyritic
Rough, Sandy
Color
Grey, White, Light Black
Brown, Brown- Black, Gold, Green, Rust
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Banded
Dull and Banded
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens
Countertops, Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
-
Curbing
Construction Industry
Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts
Artifacts
Commercial Uses
Gemstone, Laboratory bench tops, Jewelry
Cemetery Markers, Commemorative Tablets, Gemstone
Types
Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.
Translocated gossan and Leakage gossan
Features
Acidic in nature, Available in lots of colors
Clasts are smooth to touch, Easily splits into thin plates
Archaeological Significance
Formation
Rhyolite is a felsic extrusive rock and due to its high silica content, rhyolite lava is very viscous and is volcanic equivalent of granite.
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
Mineral Content
Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Grain Size
Large and Coarse Grained
Fine to Medium Grained
Fracture
Sub-conchoidal
Conchoidal
Porosity
Highly Porous
Highly Porous
Specific Gravity
2.65-2.67
2.0
Transparency
Opaque
Opaque
Density
2.4-2.6 g/cm3
-9999 g/cm3
Resistance
Heat Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India
China, India, Indonesia, Russia, Singapore, South Korea
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
Europe
Germany, Iceland, Ireland, Italy, Spain
Albania, France, Germany, Great Britain, United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New Zealand, Queensland, Western Australia
New South Wales, South Australia, Western Australia
Rhyolite vs Gossan 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. Rhyolite vs Gossan characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Rhyolite and Properties of Gossan. Learn more about Rhyolite vs Gossan in the next section. The interior uses of Rhyolite include Decorative aggregates, Homes, Hotels, Interior decoration and Kitchens whereas the interior uses of Gossan include Countertops, Decorative aggregates and Interior decoration. Due to some exceptional properties of Rhyolite and Gossan, they have various applications in construction industry. The uses of Rhyolite in construction industry include Arrowheads, As dimension stone, Building houses or walls, Construction aggregate, Cutting tool, For road aggregate, Knives and that of Gossan include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate.
More about Rhyolite and Gossan
Here you can know more about Rhyolite and Gossan. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Rhyolite and Gossan consists of mineral content and compound content. The mineral content of Rhyolite includes Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz and mineral content of Gossan includes Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon. You can also check out the list of all Igneous Rocks. When we have to compare Rhyolite vs Gossan, the texture, color and appearance plays an important role in determining the type of rock. Rhyolite is available in grey, white, light black colors whereas, Gossan is available in brown, brown- black, gold, green, rust colors. Appearance of Rhyolite is Banded and that of Gossan is Dull and Banded. Properties of rock is another aspect for Rhyolite vs Gossan. The hardness of Rhyolite is 6-7 and that of Gossan is 4-5. The types of Rhyolite are Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks. whereas types of Gossan are Translocated gossan and Leakage gossan. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Rhyolite is while that of Gossan is white to grey. The specific heat capacity of Rhyolite is 0.71 kJ/Kg K and that of Gossan is 0.24 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Rhyolite is heat resistant, wear resistant whereas Gossan is heat resistant, impact resistant, pressure resistant.