Obsidian

Blue Granite

Obsidian and Blue Granite

Obsidian

Blue Granite

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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

Blue Granite is an igneous rock and a variety of Larvikite, notable for the presence of thumbnail-sized blue crystals of feldspar

History

Origin

Ethiopia

Discoverer

Obsius

Unknown

Etymology

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

From the color of rock, Blue

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Glassy

Phaneritic

Color

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

Black, Brown, Light to Dark Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Floor Tiles, Flooring, Interior Decoration

Exterior Uses

Garden Decoration

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

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

Medical Industry

Surgery

Antiquity Uses

Artifacts, Jewellery

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Mirror, Used in aquariums

Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling

Types

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

Granite

Features

Blocks negativity, Helps to protect against depression

Available in lots of colors, Is one of the oldest 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.

Blue Granite is an igneous rock which is a variety of Larvikite and is known mainly for the presence of thumbnail-sized crystals of feldspar.

Composition

Mineral Content

Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Muscovite or Illite, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon

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, Cataclastic Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering, Chemical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Chemical Erosion, Coastal Erosion, Water Erosion

Properties

Physical Properties

Hardness

5-5.56-7

1 7

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Grain Size

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

White

Porosity

Very Less Porous

Less Porous

Luster

Vitreous

Subvitreous to Dull

Compressive Strength

0.15 N/mm²175.00 N/mm²

0.15 450

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Cleavage

Toughness

Specific Gravity

2.6-2.72.8-3

0 8.4

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Transparency

Translucent

Opaque

Density

2.6 g/cm³2.9-2.91 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, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Indonesia, Japan, Russia

Africa

Kenya

Europe

Greece, Hungary, Iceland, Italy, Turkey

Bulgaria, England, Germany, Norway, Romania, Switzerland

Others

Deposits in Western Continents

North America

Canada, Mexico, USA

USA

South America

Argentina, Chile, Ecuador, Peru

Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru

Deposits in Oceania Continent

Australia

New Zealand

New South Wales, New Zealand, Queensland, South Australia, Western Australia

All about Obsidian and Blue Granite Properties

Know all about Obsidian and Blue Granite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian and Blue Granite belong to Igneous Rocks.Texture of Obsidian is Glassy whereas that of Blue Granite is Phaneritic. Obsidian appears Shiny and Blue Granite appears Shiny. The luster of Obsidian is vitreous while that of Blue Granite is subvitreous to dull. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Blue Granite is available in black, brown, light to dark grey, white colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Blue Granite are cemetery markers, commemorative tablets, creating artwork, curling.