Definition
Whiteschist is an uncommon rock type belonging to a class of metamorphic rock, this is formed at high-ultra-high pressures
Ignimbrite is a volcanic rock consisting mainly of pumice fragments, formed by the consolidation of material deposited by pyroclastic flows
History
Origin
Tasmania
New Zealand
Discoverer
Unknown
Patrick Marshall
Etymology
From French schiste, Greek skhistos i.e. split
From Latin ignis fire + imber, imbr- shower of rain, storm cloud + -ite
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated
Aphanitic
Color
Green, Grey, White
Beige, Black, Brown, Grey, Pink, White
Maintenance
Less
More
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Banded and Foilated
Dull, Vesicular and Foilated
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
for Road Aggregate
Building houses or walls, Construction Aggregate
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Creating Artwork, Gemstone, Jewelry, Production of Lime
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
-
Pyroclastic rock
Features
High percentage of mica, Host Rock for Lead
Always found as volcanic pipes over deep continental crust
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
Whiteschist is formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.
Ignimbrites are formed from very poorly sorted mixture of volcanic ash or tuff and pumice lapilli, commonly with scattered lithic fragments.
Composition
Mineral Content
Carbonate, Coesite, Quartz, Silica
Apatite, Biotite, Calcite, Chlorite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz
Compound Content
CaO, Mg, MgO, Silicon Dioxide
Ca, NaCl
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
Burial Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Coastal Erosion
Physical Properties
Hardness
1.54-6
1
7
👆🏻
Grain Size
Fine to Medium Grained
Fine Grained
Fracture
Conchoidal
Uneven
Streak
White
White
Porosity
Less Porous
Highly Porous
Luster
Subvitreous to Dull
Vitreous to Dull
Compressive Strength
200.00 N/mm2243.80 N/mm2
0.15
450
👆🏻
Cleavage
Perfect
-
Toughness
1
-
Specific Gravity
2.862.73
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm31-1.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K0.20 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen
Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
Cameroon, Cape Verde, Chad, Djibouti, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Tanzania, Uganda
Europe
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Others
-
Antarctica, Hawaii Islands
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
Canada, Costa Rica, Panama, USA
South America
Brazil, Colombia, Guyana
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland
Central Australia, Western Australia