Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Diatomite is a fine-grained sedimentary rock which is formed from consolidated diatomaceous earth
History
Origin
Hawaii Islands
Germany
Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
From diatom + -ite1
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Family
Group
Volcanic
-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Earthy, Rough
Clastic or Non-Clastic
Color
Black, Brown, Green, Grey, Pink, White, Yellow
Grey, White, Yellow
Maintenance
Less
Less
Durability
Durable
Non-Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Rough and Shiny
Soft
Architecture
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
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.
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Source of calcium
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Other Uses
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Alumina Refineries, Animal feed filler, As a Feed Additive for Livestock, Creating Artwork, Drawing on blackboards, Fire resistant, Gymnasts, athletes and mountain climbers use for grip, In aquifers, Soil Conditioner, To ignite fire, Used as a filter medium, Used as an insecticide, Whiting material in toothpaste, paint and paper
Types
Oceanite
Diatomite
Features
Host Rock for Lead
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
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.
Diatomite rock formed from the skeletal remains of single celled plants called diatoms. When diatoms die, their skeletal remains sink to the bottom of lakes and oceans etc. hence forming diatomite deposit.
Composition
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Calcite, Clay, Clay Minerals, Quartz, Sand
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
Ca, NaCl, CaO
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Wind Erosion
Physical Properties
Hardness
6.81
1
7
👆🏻
Grain Size
Fine Grained
Very fine-grained
Fracture
Uneven
-
Streak
White, Greenish White or Grey
White
Porosity
Less Porous
Highly Porous
Luster
Subvitreous to Dull
Dull
Compressive Strength
189.00 N/mm2-
0.15
450
👆🏻
Cleavage
-
-
Toughness
2.1
1
Specific Gravity
2.75-2.922.3-2.4
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
1.5-2.5 g/cm32.49-2.51 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.88 kJ/Kg K0.90 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
India, Russia
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
Africa
South Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Europe
Iceland
England, France, Germany, Spain, United Kingdom
Others
-
-
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Colombia
Deposits in Oceania Continent
Australia
-
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula