Definition
Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals
Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock
Discoverer
R. J. Hauy
Unknown
Etymology
From Greek pegma, pegmat which means- thing joined together + -ite
From German which means hornstone
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Pegmatitic
Granular, Platy
Color
Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow
Brown, Dark Greenish - Grey, Green, Reddish Brown
Durability
Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Dull
Interior Uses
Decorative Aggregates, Flooring, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone
As Building Stone, As Facing 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
for Road Aggregate, Roadstone
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Monuments
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
Biotite hornfels
Features
Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz
Smooth to touch
Archaeological Significance
Formation
Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz
Andalusite
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide
Fe, Mg
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Coarse Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Porosity
Less Porous
Highly Porous
Luster
Grainy, Pearly and Vitreous
Shiny
Specific Gravity
2.6-2.63
3.4-3.9
Transparency
Translucent to Opaque
Opaque
Density
2.6-2.65 g/cm3
0.25-0.30 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Africa
South Africa
Cameroon, East Africa, Tanzania, Western Africa
Europe
Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine
United Kingdom
Deposits in Western Continents
North America
Canada
Canada, USA
South America
Brazil
Bolivia, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
New South Wales, New Zealand, Queensland, Western Australia
All about Pegmatite and Hornfels Properties
Know all about Pegmatite and Hornfels properties here. All properties of rocks are important as they define the type of rock and its application. Pegmatite belongs to Igneous Rocks while Hornfels belongs to Metamorphic Rocks.Texture of Pegmatite is Pegmatitic whereas that of Hornfels is Granular, Platy. Pegmatite appears Layered, Banded, Veined and Shiny and Hornfels appears Dull. The luster of Pegmatite is grainy, pearly and vitreous while that of Hornfels is shiny. Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors whereas Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. The commercial uses of Pegmatite are creating artwork, jewelry, source of corundum, tourmalines, beryls and topaz and that of Hornfels are cemetery markers, commemorative tablets, creating artwork.