Obsidian

Granophyre

Obsidian and Granophyre

Obsidian

Granophyre

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Definition

Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth

Granophyre is a type of granitic rock which consists of intergrown feldspar and quartz crystals in a medium to fine grained groundmass

History

Origin

Ethiopia

Discoverer

Obsius

Unknown

Etymology

From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius

From German Granophyr, from Granit granite + Porphyr

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Glassy

Granophyric

Color

Black, Blue, Brown, Green, Orange, Red, Tan, Yellow

Black, Grey, Orange, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Shiny

Veined or Pebbled

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Bathrooms, Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads

Exterior Uses

Garden Decoration

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

Other Architectural Uses

Industry

Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

As Dimension Stone

Medical Industry

Surgery

Antiquity Uses

Artifacts, Jewellery

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Mirror, Used in aquariums

Curling, Gemstone, Laboratory bench tops, Tombstones

Types

Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian

Intermediate intrusive rock

Features

Blocks negativity, Helps to protect against depression

Available in Lots of Colors and Patterns, It is One of the Oldest, Strongest and Hardest Rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.

Granophyre 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

Hornblade, Orthoclase, Plagioclase, Quartz

Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Burial Metamorphism, Impact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Glacier Erosion, Sea Erosion, Wind Erosion

Properties

Physical Properties

Hardness

5-5.56-7

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

White

Porosity

Very Less Porous

Less Porous

Luster

Vitreous

Dull to Grainy with Sporadic parts Pearly and Vitreous

Compressive Strength

0.15 N/mm²175.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

Specific Gravity

2.6-2.72.6-2.7

0 8.4

👆🏻

Transparency

Translucent

Opaque

Density

2.6 g/cm³2.6-2.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.79 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Indonesia, Japan, Russia

China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam

Africa

Kenya

Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa

Europe

Greece, Hungary, Iceland, Italy, Turkey

Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic

Others

Deposits in Western Continents

North America

Canada, Mexico, USA

Canada, USA

South America

Argentina, Chile, Ecuador, Peru

Deposits in Oceania Continent

Australia

New Zealand

All about Obsidian and Granophyre Properties

Know all about Obsidian and Granophyre properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian and Granophyre belong to Igneous Rocks.Texture of Obsidian is Glassy whereas that of Granophyre is Granophyric. Obsidian appears Shiny and Granophyre appears Veined or Pebbled. The luster of Obsidian is vitreous while that of Granophyre is dull to grainy with sporadic parts pearly and vitreous. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Granophyre is available in black, grey, orange, pink, white colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Granophyre are curling, gemstone, laboratory bench tops, tombstones.