Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Novaculite is a dense, hard, fine-grained, siliceous metamorpic rock which is a type of chert that breaks with conchoidal fracture
Origin
Hawaii Islands
Unknown
Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
From Latin word novacula, for razor stone
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Earthy, Rough
Banded, Glassy, Rough, Vitreous
Color
Black, Brown, Colourless, Green, Grey, Pink, White, Yellow
Black, Brown, Green, Grey, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Rough and Shiny
Glassy or Pearly
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.
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
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
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
Types
Oceanite
Not Available
Features
Host Rock for Lead
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Used
Not Yet Used
Formation
Picrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
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.
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Quartz, Silicon
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
Ca, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering
Not Applicable
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Uneven
Conchoidal
Streak
White, Greenish White or Grey
Colorless
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Waxy and Dull
Cleavage
Imperfect
Non-Existent
Specific Gravity
2.75-2.92
2.5-2.7
Transparency
Opaque
Translucent to Opaque
Density
1.5-2.5 g/cm3
2.7 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
South Africa
Kenya, Morocco, South Africa, Tanzania
Europe
Iceland
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Not Yet Found
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Brazil
Bolivia, Brazil
Deposits in Oceania Continent
Australia
Not Yet Found
New South Wales, Queensland, South Australia, Western Australia
All about Picrite and Novaculite Properties
Know all about Picrite and Novaculite properties here. All properties of rocks are important as they define the type of rock and its application. Picrite belongs to Igneous Rocks while Novaculite belongs to Sedimentary Rocks.Texture of Picrite is Earthy, Rough whereas that of Novaculite is Banded, Glassy, Rough, Vitreous. Picrite appears Rough and Shiny and Novaculite appears Glassy or Pearly. The luster of Picrite is subvitreous to dull while that of Novaculite is waxy and dull. Picrite is available in black, brown, colourless, green, grey, pink, white, yellow colors whereas Novaculite is available in black, brown, green, grey, red, white colors. The commercial uses of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo) and that of Novaculite are 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.