Definition
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Hawaiite is volcanic rock that resembles basalt. It is an olivine basalt with intermediate composition between alkali olivine and mugearite
History
Origin
Italy
Hawaii Islands
Discoverer
Unknown
Joseph Iddings
Etymology
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
From Hawaii Islands
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Volcanic
Other Categories
Medium Grained Rock, Opaque Rock
Opaque Rock
Texture
Porphyritic
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Blue, Bluish - Grey
Black, Brown, Light to Dark Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Foliated
Dull and Soft
Architecture
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Raw material for the manufacture of mortar
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
-
-
Antiquity Uses
Artifacts
Artifacts
Other Uses
Commercial Uses
Cemetery Markers
Creating Artwork, Sea Defence
Types
Rhyolite
Volcanic rock
Features
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
Easter Island in the Polynesian Triangle, Pacific Ocean
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
Comendite is a type of Igneous rock which is formed due to cooling and solidification of lava or magma. It may form with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Hawaiite is a fine-grained, hard rock that forms when bits of lava shoot out of volcanoes and reach the Earth's surface.
Composition
Mineral Content
Albite, Amphibole, Quartz
Olivine, Plagioclase, Pyroxene
Compound Content
Al, Fe, Potassium Oxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Impact Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Coastal Erosion, Water Erosion
-
Physical Properties
Hardness
6-76
1
7
👆🏻
Grain Size
Medium Grained
-
Fracture
Pervasive
Conchoidal
Streak
Bluish Black
-
Porosity
Highly Porous
Less Porous
Luster
Dull
-
Compressive Strength
92.40 N/mm237.40 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
2
-
Specific Gravity
2.38-9999
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
-9999 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.79 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China
India, Russia
Africa
East Africa
South Africa
Europe
Italy
Iceland
Others
-
Hawaii Islands
Deposits in Western Continents
North America
-
Canada, USA
South America
-
Brazil
Deposits in Oceania Continent
Australia
Queensland
-