Gossan

Nephelinite

Gossan and Nephelinite

Gossan

Nephelinite

Add ⊕

Definition

Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.

Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).

History

Origin

Indonesia

Brazil

Discoverer

Cornish Gossen

Unknown

Etymology

From Cornish gossen from gos, blood from Old Cornish guit

from French néphéline, from Greek nephelē

Class

Metamorphic Rocks

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Rough, Sandy

Aphanitic

Color

Brown, Brown- Black, Gold, Green, Rust

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Banded

Skeletal

Uses

Architecture

Interior Uses

Countertops, Decorative Aggregates, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings

As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Gemstone

Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)

Types

Translocated gossan and Leakage gossan

Peralkaline Nephelinite

Features

Clasts are smooth to touch, Easily splits into thin plates

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.

Nephelinite 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.

Composition

Mineral Content

Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon

Clinopyroxene, Nepheline, Plagioclase

Compound Content

Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur

Ca, CaO, Carbon, Cl, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Sea Erosion, Wind Erosion

Chemical Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

4-56.5

1 7

👆🏻

Grain Size

Fine to Medium Grained

Fine Grained

Fracture

Conchoidal

Flat

Streak

White to Grey

White

Porosity

Highly Porous

Less Porous

Luster

Metallic

Vitreous to Metallic

Compressive Strength

-35.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.7

Specific Gravity

2.02.4-2.9

0 8.4

👆🏻

Transparency

Opaque

Density

-9999 g/cm³2.5-3 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.24 kJ/Kg K0.88 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Indonesia, Russia, Singapore, South Korea

Japan

Africa

Cape Verde, Ethiopia, Ghana, South Africa, Western Africa

Rwanda, Tanzania

Europe

Albania, France, Germany, Great Britain, United Kingdom

Others

Hawaii Islands

Deposits in Western Continents

North America

Canada, USA

South America

Brazil, Colombia, Ecuador

Colombia

Deposits in Oceania Continent

Australia

New South Wales, South Australia, Western Australia

All about Gossan and Nephelinite Properties

Know all about Gossan and Nephelinite properties here. All properties of rocks are important as they define the type of rock and its application. Gossan belongs to Metamorphic Rocks while Nephelinite belongs to Igneous Rocks.Texture of Gossan is Rough, Sandy whereas that of Nephelinite is Aphanitic. Gossan appears Dull and Banded and Nephelinite appears Skeletal. The luster of Gossan is metallic while that of Nephelinite is vitreous to metallic. Gossan is available in brown, brown- black, gold, green, rust colors whereas Nephelinite is available in black, brown, green, grey, white colors. The commercial uses of Gossan are cemetery markers, commemorative tablets, gemstone and that of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo).