Definition
Breccia is a rock consisting of angular fragments of stones which are cemented by finer calcareous material
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
History
Origin
England
New Zealand
Discoverer
Unknown
Unknown
Etymology
From Italian, literally gravel, Germanic origin and related to break
From German which means hornstone
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Family
Group
-
-
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Brecciated, Clastic
Granular, Platy
Color
Beige, Black, Blue, Brown, Buff, Green, Grey, Orange, Pink, Purple, Red, Rust, White, Yellow
Brown, Dark Greenish - Grey, Green, Reddish Brown
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Layered, Banded, Veined and Shiny
Dull
Architecture
Interior Uses
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Construction Aggregate, Landscaping, Roadstone
for Road Aggregate, Roadstone
Medical Industry
-
-
Antiquity Uses
Artifacts, Sculpture
Artifacts, Monuments
Other Uses
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Collapse Breccia, Fault Breccia, Flow Breccia, Pyroclastic Breccia, Igneous Breccia and Impact Breccia
Biotite hornfels
Features
Available in Lots of Colors and Patterns, Clasts are smooth to touch
Smooth to touch
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Present
Absent
Formation
Breccia is a clastic sedimentary rock which is composed of broken fragments of minerals or rock which are cemented together by a fine-grained matrix and it forms where broken, angular fragments of rock or mineral debris accumulate.
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.
Composition
Mineral Content
Calcite, Clay, Feldspar, Phosphates, Quartz, Silica
Andalusite
Compound Content
Aluminium Oxide, Ca, NaCl, CaO, Iron(III) Oxide, Potassium Oxide, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Fe, Mg
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
72-3
1
7
👆🏻
Grain Size
Medium to Coarse Grained
Fine Grained
Fracture
Uneven
Conchoidal
Streak
White
-
Porosity
Less Porous
Highly Porous
Luster
Dull to Pearly
Shiny
Compressive Strength
180.00 N/mm25.80 N/mm2
0.15
450
👆🏻
Cleavage
-
Perfect
Toughness
-
-
Specific Gravity
2.86-2.873.4-3.9
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
0 g/cm30.25-0.30 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India, Kazakhstan, Mongolia, Russia, South Korea, Uzbekistan
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Africa
Namibia, Nigeria, South Africa
Cameroon, East Africa, Tanzania, Western Africa
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
United Kingdom
Others
Greenland
-
Deposits in Western Continents
North America
Barbados, Canada, Mexico, Panama, USA
Canada, USA
South America
Brazil
Bolivia, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New South Wales, New Zealand
New South Wales, New Zealand, Queensland, Western Australia