Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
A ganister is a hard, fine-grained quartzose sandstone or orthoquartzite which is basically used in the manufacture of silica brick typically used to line furnaces and is a type of sedimentary rocks.
History
Origin
Hawaii Islands
England
Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
From gan′is-ter i.e a hard, close-grained siliceous stone, often forming the stratum which underlies a coal-seam
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
-
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
Texture
Earthy, Rough
Clastic, Granular, Rough
Color
Black, Brown, Green, Grey, Pink, White, Yellow
Beige, Black, Brown, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Rough and Shiny
Rough
Architecture
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, Garden Decoration, Office Buildings, 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.
Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
An Oil and Gas Reservoir, In aquifers, Petroleum reservoirs, Soil Conditioner, Source of Magnesia (MgO), Tombstones
Types
Oceanite
Siliceous rock
Features
Host Rock for Lead
Available in Lots of Colors and Patterns, Generally rough 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.
Ganisters are formed by the destruction of easily weathered minerals mainly feldspar, within the surface horizon of soil by soil-forming processes.
Composition
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering
Biological Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Water Erosion, Wind Erosion
Physical Properties
Hardness
6.86-7
1
7
👆🏻
Grain Size
Fine Grained
Coarse or Fine
Fracture
Uneven
Splintery
Streak
White, Greenish White or Grey
White
Porosity
Less Porous
Highly Porous
Luster
Subvitreous to Dull
Dull
Compressive Strength
189.00 N/mm295.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Perfect
Toughness
2.1
2.6
Specific Gravity
2.75-2.922.2-2.8
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
1.5-2.5 g/cm32.2-2.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.88 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
South Africa
Namibia, Nigeria, South Africa
Europe
Iceland
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Others
-
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Brazil
Deposits in Oceania Continent
Australia
-
New South Wales, New Zealand