Obsidian

Phyllite

Obsidian and Phyllite

Obsidian

Phyllite

Add ⊕

1 Definition

1.1 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

Phyllite is a fine-grained metamorphic rock with a well-developed laminar structure, and is intermediate between slate and schist rocks

1.2 History

1.2.1 Origin

Ethiopia

Unknown

1.2.2 Discoverer

Obsius

Unknown

1.3 Etymology

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

From Greek phullon leaf + -ite1

1.4 Class

Igneous Rocks

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Volcanic

Not Applicable

1.6 Other Categories

Opaque Rock

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

2 Texture

2.1 Texture

Glassy

Phyllitic Sheen, Slaty

2.2 Color

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

Black to Grey, Light Greenish Grey

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

81% Igneous Rocks Rocks have it !

✔ ✘

81% Metamorphic Rocks Rocks have it !

2.4.2 Scratch Resistant

✔ ✘

86% Igneous Rocks Rocks have it !

✔ ✘

65% Metamorphic Rocks Rocks have it !

2.4.3 Stain Resistant

✔ ✘

66% Igneous Rocks Rocks have it !

✔ ✘

42% Metamorphic Rocks Rocks have it !

2.4.4 Wind Resistant

✔ ✘

49% Igneous Rocks Rocks have it !

✔ ✘

19% Metamorphic Rocks Rocks have it !

2.4.5 Acid Resistant

✔ ✘

48% Igneous Rocks Rocks have it !

✔ ✘

15% Metamorphic Rocks Rocks have it !

2.5 Appearance

Shiny

Crinkled or Wavy

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Floor Tiles, Homes, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration

As Building Stone, As Facing Stone, Garden Decoration

3.1.3 Other Architectural Uses

Not Yet Used

Curbing

3.2 Industry

3.2.1 Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar, Roadstone

3.2.2 Medical Industry

Surgery

Not Yet Used

3.3 Antiquity Uses

Artifacts, Jewellery

Artifacts, Sculpture

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Mirror, Used in aquariums

Cemetery Markers, Commemorative Tablets, Creating Artwork, Writing Slates

4 Types

4.1 Types

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

Not Available

4.2 Features

Blocks negativity, Helps to protect against depression

Easily splits into thin plates, Is one of the oldest rock, Surfaces are often shiny

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

4.3.2 Famous Monuments

Not Applicable

4.3.3 Sculpture

Not Yet Used

Used

4.3.4 Famous Sculptures

Not Applicable

Data Not Available

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Not Yet Used

Used

4.4 Fossils

Absent

5 Formation

5.1 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.

Phyllite is a metamorphic rock which is formed by regional metamorphism of argillaceous sediments since their cleavage arose due to deviatoric stress.

5.2 Composition

5.2.1 Mineral Content

Not Available

Albite, Alusite, Amphibole, Apatite, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc, Zircon

5.2.2 Compound Content

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

CaO, Carbon Dioxide, MgO

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

97% Igneous Rocks Rocks have it !

✔ ✘

50% Metamorphic Rocks Rocks have it !

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Not Applicable

5.3.3 Weathering

✔ ✘

99% Igneous Rocks Rocks have it !

✔ ✘

65% Metamorphic Rocks Rocks have it !

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

92% Igneous Rocks Rocks have it !

✔ ✘

77% Metamorphic Rocks Rocks have it !

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5-5.5

1-2

6.1.2 Grain Size

Not Applicable

Medium to Fine Coarse Grained

6.1.3 Fracture

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Very Less Porous

Highly Porous

6.1.6 Luster

Vitreous

Phyllitic

6.1.7 Compressive Strength

What Is Flint

⊕

▶

▼

0.15 N/mm²

Rank: 33 (Overall)▶

Not Available

Rank: N/A (Overall)▶

▲

What Is Obsidian

⊕

▶

175 (What Is Grani..)

◀ ▶ ADD ⊕

6.1.8 Cleavage

Non-Existent

Crenulation and Pervasive

6.1.9 Toughness

Not Available

1.2

6.1.10 Specific Gravity

2.6-2.7

2.72-2.73

6.1.11 Transparency

Translucent

Opaque

6.1.12 Density

2.6 g/cm³

2.18-3.3 g/cm³

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

What Is Banded ..

⊕

▶

▼

0.92 kJ/Kg K

Rank: 10 (Overall)▶

Not Available

Rank: N/A (Overall)▶

▲

What Is Granulite

⊕

▶

1.09 (What Is Trave..)

◀ ▶ ADD ⊕

6.2.2 Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Pressure Resistant, Water Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Afghanistan, Indonesia, Japan, Russia

Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam

7.1.2 Africa

Kenya

Egypt, Ethiopia, Morocco, Nigeria, South Africa

7.1.3 Europe

Greece, Hungary, Iceland, Italy, Turkey

Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Mexico, USA

Canada, Costa Rica, Cuba, Mexico, Panama, USA

7.2.2 South America

Argentina, Chile, Ecuador, Peru

Brazil, Colombia, Guyana

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand

New South Wales, New Zealand, Queensland

All about Obsidian and Phyllite Properties

Know all about Obsidian and Phyllite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Phyllite belongs to Metamorphic Rocks.Texture of Obsidian is Glassy whereas that of Phyllite is Phyllitic Sheen, Slaty. Obsidian appears Shiny and Phyllite appears Crinkled or Wavy. The luster of Obsidian is vitreous while that of Phyllite is phyllitic. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Phyllite is available in black to grey, light greenish grey colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Phyllite are cemetery markers, commemorative tablets, creating artwork, writing slates.