Definition
Novaculite is a dense, hard, fine-grained, siliceous metamorpic rock which is a type of chert that breaks with conchoidal fracture
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism
History
Origin
-
England
Discoverer
Unknown
Abraham Gottlob Werner
Etymology
From Latin word novacula, for razor stone
From Old French esclate, from esclat (French éclat)
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Banded, Glassy, Rough, Vitreous
Foliated
Color
Black, Brown, Green, Grey, Red, White
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Glassy or Pearly
Dull
Architecture
Interior Uses
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Exterior Uses
As Building Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Arrowheads, Building houses or walls, Cement Manufacture, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives, Landscaping, Making natural cement, Production of Glass and Ceramics, Rail Track Ballast, Roadstone, Spear Points, Used to sharpen metal tools and weapons
As Dimension Stone
Medical Industry
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-
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Cemetery Markers, Gemstone, In aquifers, In fire-starting tools, Jewelry, Manufacture of tools, Pebbles are used in ball mills to grind in ceramics industry, To determine the gold content of jewelry
Blackboards, Commemorative Tablets, Laboratory bench tops, Standard material for the bed of Billiard table, Standard material for the beds of Pool and Snooker table, Tombstones, Used in aquariums, Writing Slates
Types
Sedimentary rock
Phyllite, Schist, and Slate
Features
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Present
Absent
Formation
Novaculite forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The formation of Novaculite can be either of chemical or biological origin.
Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.
Composition
Mineral Content
Quartz, Silicon
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Compound Content
Ca, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
73-4
1
7
👆🏻
Grain Size
Fine Grained
Very fine-grained
Fracture
Conchoidal
Splintery
Streak
-
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Waxy and Dull
Dull
Compressive Strength
450.00 N/mm230.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Slaty
Toughness
1.5
1.2
Specific Gravity
2.5-2.72.65-2.8
0
8.4
👆🏻
Transparency
Translucent to Opaque
Opaque
Density
2.7 g/cm32.6-2.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.74 kJ/Kg K0.76 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
China, India, Turkey
Africa
Kenya, Morocco, South Africa, Tanzania
-
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Others
Greenland, Mid-Atlantic Ridge
Arctic
Deposits in Western Continents
North America
Canada, Mexico, USA
USA
South America
Bolivia, Brazil
Brazil
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
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