Definition
Troctolite is a mafic intrusive rock type. It consists essentially of major but variable amounts of olivine and calcic plagioclase along with minor pyroxene. It is an olivine-rich anorthosite, or a pyroxene-depleted relative of gabbro
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Discoverer
Christian Leopold von Buch
Alexandre Brongniart and René Just Haüy
Etymology
From German Troklotit, from Greek trōktēs, a marine fish (taken to be trout)
From Greek trakhus rough’ or trakhutēs roughness
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Phaneritic
Aphanitic to Porphyritic
Color
Dark Grey to Black
Black, Brown, Dark Greenish - Grey, Green, Grey, Light to Dark Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Veined and Shiny
Banded
Interior Uses
Bathrooms, Countertops, Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration, Kitchens
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Antiquity Uses
Artifacts, Jewellery, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Cemetery Markers, Creating Artwork
Types
Ultramafic rock
Felsic volcanic rock
Features
Smooth to touch
Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable
Archaeological Significance
Formation
Troctolite 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.
Trachyte is an igneous volcanic rock with an aphanitic to porphyritic texture. It is the volcanic equivalent of syenite rock and forms as a result of magmatic differentiation.
Mineral Content
Augite, Olivine, Plagioclase, Pyroxene
Augite, Biotite, Feldspar, Hornblade, Plagioclase, Quartz
Compound Content
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Potassium Oxide, Sodium Oxide, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Types of Weathering
Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Coarse Grained
Fine Grained
Porosity
Highly Porous
Less Porous
Specific Gravity
2.86-2.87
2.7
Transparency
Opaque
Opaque
Density
2.7-3.3 g/cm3
2.43-2.45 g/cm3
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
South Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Germany, Greece, Italy, Scotland, Turkey
Bulgaria, England, Germany, Norway, Romania, Switzerland
Deposits in Western Continents
North America
Canada, USA
USA
South America
Brazil, Colombia, Venezuela
Brazil, Chile
Deposits in Oceania Continent
Australia
New Zealand, Queensland
New Zealand, Queensland, South Australia, Western Australia