Pumice

Picrite

Pumice and Picrite

Pumice

Picrite

Add ⊕

Definition

Pumice is a volcanic rock that consists of highly vesicular rough textured volcanic glass, which may or may not contain crystals

Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine

History

Origin

Spain

Hawaii Islands

Discoverer

Unknown

Etymology

From Old French pomis, from a Latin dialect variant of pumex

From Greek pikros bitter + -ite, 19th century

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Vesicular

Earthy, Rough

Color

Beige, Grey, Light Green, Light Grey, Pink, White, Yellow- grey

Black, Brown, Green, Grey, Pink, White, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Vesicular

Rough and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Countertops, Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

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

Other Architectural Uses

Curbing, Powder

Curbing

Industry

Construction Industry

As Dimension Stone, Cement Manufacture, for Road Aggregate, In landscaping and horticulture, Making natural cement, Production of lightweight concrete blocks

As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.

Medical Industry

As an abrasive in skin exfoliating products, In Chemical and Pharmaceutical Industry, Medicines and Cosmetics

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

As a traction material on snow-covered roads, As an abrasive in pencil erasers, Fine abrasive used for polishing, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Used in aquariums

As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)

Types

Scoria

Oceanite

Features

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Pumice rock forms when the magma cools so quickly that atoms in the melt are not able to arrange themselves into a crystalline structure.

Picrite 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

Aluminum Oxides, Calcite, Carbonate, Iron Oxides, Silica

Biotite, Olivine, Plagioclase, Pyrrhotite

Compound Content

Al, Aluminium Oxide, CaO, Carbon Dioxide, MgO, Silicon Dioxide

Al, CaO, Carbon Dioxide, Mg, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Impact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering

Erosion

✔ ✘

Types of Erosion

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

Properties

Physical Properties

Hardness

66.8

1 7

👆🏻

Grain Size

Fine Grained

Fracture

Planar

Uneven

Streak

White, Greenish White or Grey

Porosity

Highly Porous

Less Porous

Luster

Earthy

Subvitreous to Dull

Compressive Strength

51.20 N/mm²189.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

2.1

Specific Gravity

2.862.75-2.92

0 8.4

👆🏻

Transparency

Opaque

Density

0.25-0.3 g/cm³1.5-2.5 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.87 kJ/Kg K0.88 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Impact Resistant, Pressure Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Indonesia, Japan, Russia

India, Russia

Africa

Ethiopia, Kenya, Tanzania

South Africa

Europe

Greece, Hungary, Iceland, Italy, Turkey

Iceland

Others

Deposits in Western Continents

North America

Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA

Canada, USA

South America

Argentina, Chile, Ecuador, Peru

Brazil

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

All about Pumice and Picrite Properties

Know all about Pumice and Picrite properties here. All properties of rocks are important as they define the type of rock and its application. Pumice and Picrite belong to Igneous Rocks.Texture of Pumice is Vesicular whereas that of Picrite is Earthy, Rough. Pumice appears Vesicular and Picrite appears Rough and Shiny. The luster of Pumice is earthy while that of Picrite is subvitreous to dull. Pumice is available in beige, grey, light green, light grey, pink, white, yellow- grey colors whereas Picrite is available in black, brown, green, grey, pink, white, yellow colors. The commercial uses of Pumice are as a traction material on snow-covered roads, as an abrasive in pencil erasers, fine abrasive used for polishing, manufacture of soap, solvents, dyes, plastics and fibres, used in aquariums and that of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo).