Definition
Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals
Ignimbrite is a volcanic rock consisting mainly of pumice fragments, formed by the consolidation of material deposited by pyroclastic flows
Discoverer
R. J. Hauy
Patrick Marshall
Etymology
From Greek pegma, pegmat which means- thing joined together + -ite
From Latin ignis fire + imber, imbr- shower of rain, storm cloud + -ite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Pegmatitic
Aphanitic
Color
Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow
Beige, Black, Brown, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Layered, Banded, Veined and Shiny
Dull, Vesicular and Foilated
Interior Uses
Decorative Aggregates, Flooring, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping
Building houses or walls, Construction Aggregate
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite
Pyroclastic rock
Features
Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz
Always found as volcanic pipes over deep continental crust
Archaeological Significance
Formation
Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.
Ignimbrites are formed from very poorly sorted mixture of volcanic ash or tuff and pumice lapilli, commonly with scattered lithic fragments.
Mineral Content
Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz
Apatite, Biotite, Calcite, Chlorite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide
Ca, NaCl
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion
Grain Size
Medium to Coarse Grained
Fine Grained
Fracture
Conchoidal
Uneven
Porosity
Less Porous
Highly Porous
Luster
Grainy, Pearly and Vitreous
Vitreous to Dull
Specific Gravity
2.6-2.63
2.73
Transparency
Translucent to Opaque
Opaque
Density
2.6-2.65 g/cm3
1-1.8 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea
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
South Africa
Cameroon, Cape Verde, Chad, Djibouti, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Tanzania, Uganda
Europe
Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Others
-
Antarctica, Hawaii Islands
Deposits in Western Continents
North America
Canada
Canada, Costa Rica, Panama, USA
South America
Brazil
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
Central Australia, Western Australia
Pegmatite vs Ignimbrite 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. Pegmatite vs Ignimbrite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Pegmatite and Properties of Ignimbrite. Learn more about Pegmatite vs Ignimbrite in the next section. The interior uses of Pegmatite include Decorative aggregates, Flooring and Interior decoration whereas the interior uses of Ignimbrite include Decorative aggregates, Floor tiles, Homes and Interior decoration. Due to some exceptional properties of Pegmatite and Ignimbrite, they have various applications in construction industry. The uses of Pegmatite in construction industry include As dimension stone, Building houses or walls, Construction aggregate, For road aggregate, Landscaping and that of Ignimbrite include Building houses or walls, Construction aggregate.
More about Pegmatite and Ignimbrite
Here you can know more about Pegmatite and Ignimbrite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Pegmatite and Ignimbrite consists of mineral content and compound content. The mineral content of Pegmatite includes Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz and mineral content of Ignimbrite includes Apatite, Biotite, Calcite, Chlorite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz. You can also check out the list of all Igneous Rocks. When we have to compare Pegmatite vs Ignimbrite, the texture, color and appearance plays an important role in determining the type of rock. Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors whereas, Ignimbrite is available in beige, black, brown, grey, pink, white colors. Appearance of Pegmatite is Layered, Banded, Veined and Shiny and that of Ignimbrite is Dull, Vesicular and Foilated. Properties of rock is another aspect for Pegmatite vs Ignimbrite. The hardness of Pegmatite is 7 and that of Ignimbrite is 4-6. The types of Pegmatite are Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite whereas types of Ignimbrite are Pyroclastic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Pegmatite and Ignimbrite is white. The specific heat capacity of Pegmatite is 0.79 kJ/Kg K and that of Ignimbrite is 0.20 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Pegmatite is heat resistant, impact resistant, pressure resistant whereas Ignimbrite is heat resistant, impact resistant, pressure resistant, wear resistant.