Definition
Mudstone is a fine-grained, dark gray sedimentary rock, which is formed from silt and clay and is similar to shale but has less laminations
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
Discoverer
Unknown
Unknown
Etymology
From the English mud and stone, from low German mudde and stainaz
From German Tachylite, from tachy- + Greek lutos soluble, melting
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Group
Not Applicable
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Color
Black, Blue, Brown, Green, Grey, Orange, Red, White, Yellow
Black, Dark Brown
Durability
Durable
Durable
Appearance
Rough and Dull
Glassy
Interior Uses
Decorative Aggregates, Entryways, Floor Tiles, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Roof Tiles
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Cutting Tool, Knives, Landscaping, Scrapers
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Sculpture, Small Figurines
Artifacts
Commercial Uses
Creating Artwork, Pottery
Cemetery Markers, Creating Artwork
Types
Marl, Shale and Argillite
Not Available
Features
Available in Lots of Colors and Patterns, Smooth to touch, Very fine grained rock
Available in Lots of Colors and Patterns, Clasts are smooth to touch, NA
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Figurines
Used
Not Yet Used
Formation
Mudstone forms when very fine-grained clay particles are deposited in water which settle at the bottom of water bodies. They are buried and compacted by overlying sediment hence forming mudstone.
Tachylite 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.
Mineral Content
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Feldspar, Olivine
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, Silicon Dioxide
Fe, Mg
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Very fine-grained
Medium to Fine Coarse Grained
Fracture
Not Available
Conchoidal
Porosity
Highly Porous
Less Porous
Compressive Strength
Not Available
Cleavage
Perfect
Not Available
Toughness
2.6
Not Available
Specific Gravity
2.2-2.8
2.4
Transparency
Opaque
Opaque
Density
2.4-2.8 g/cm3
3.058 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, China, India, Russia
Cambodia, Russia, South Korea
Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
East Africa
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
England, Germany, Hungary, Iceland, Scotland, Sweden
Others
Not Yet Found
Hawaii Islands
Deposits in Western Continents
South America
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Not Yet Found
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia
Victoria