•  Pumex UK

    Worldwide Distributors of Pumice

  • Pumice for Abrasion Applications

  • Pumice for Agriculture

  • Pumice for Construction

  • Pumice for Cosmetics

  • Pumice for Filtration

  • Pumice for Stonewashing

Pumex UK 

Worldwide Distributors of Pumice

The activities of Pumex (UK) have recently been taken over by Richard Baker Harrison Limited. We offer high quality pumice powders, grains and aggregates.

Stocks are kept in the UK to enable prompt delivery to you.

Pumice Applications







Pumice is a very porous, froth-like volcanic glass that has long been used as an abrasive in cleaning, polishing, and scouring compounds. It is also used in precast masonry units, poured concrete, insulation and acoustic tile, and plaster. Pumice is igneous rock that has cooled so rapidly there was no time for it to crystallise. When it solidified, the vapours dissolved in it were suddenly released and the whole mass swelled up into a froth that immediately consolidated.

Pumice is formed deep in the earth’s crust. Magma pockets are formed by a partial melting of basalt, under high pressure conditions this magma absorbs substances that under normal conditions are fluid or gaseous ( H2O, CO2, F). At certain periods in time when the pressure above a magma pocket is relieved (as in the case in an earthquake) a volcanic eruption starts and these gases are released from the magma in an explosive outburst. Due to the liberation of the gases the viscosity of the magma increases very rapidly and the solidifying temperature rises to that of the reigning pressure. Thus as the magma froths, it is fragmented and solidifies forming the cellular material we know as pumice.

This material is flung high up into the air together with an enormous stream of gases from the crater and is carried out over the surrounding land.

The Chemical and Physical Characteristics of Pumice:

The general chemical analysis of pumice is:

  • SiO2
    74.13 %
  • Al2O3
    11.8 %
  • Fe2O3
    1.39 %
  • MgO
    0.02 %
  • CaO
    0.32 %
  • Na2O
    3.50 %
  • K2O
    4.33 %
  • MnO
    0.05 %
  • TiO2
    0.08 %
  • Loss on Ignition
    4.28 %

The high percentage of Silicon Dioxide gives the pumice its abrasive quality, and a chemical composition that can easily erode steel.   The Al2O3 in the structure makes the pumice highly resistant to fire and heat. Na2O and K2O are the minerals which give the pumice the reaction sought after by the textiles industry.

Pumice is of either acidic or basaltic nature. Basaltic pumice, also known as scoria, is dark brown to black in colour and has a specific weight of about 1-2 gr/cm3. Acidic pumice, known simply as pumice, is white, however due to the density of acidic magma being much lower than that of basaltic pumice. Its specific weight is also much lower, at about 0.5-1 gr/cm3. The high level of SiO2 gives this pumice its white colour.

The physical properties of pumice are governed by the extremely cellular structure of the matrix. These cells are independent of each other, which means the level of sound and heat conductivity are extremely low. The hardness of pumice is approximately 6 – 6.5 on the mohs scale – and does not contain crystallised water in it’s structure. It is chemically inert and possesses about 70-75% Silicon Dioxide. Due to the microscopic size of the pores, which make up about 85% of the pumice grain volume, pumice is an extremely light rock which is able to float on the surface.


History of Pumice

The earliest known reference its special properties are found in Vitruvio’s compendium of architecture of the First Century BC. Vitruvio describes artificial agglomerates lighter than water, and buoyant, containing an inert pumice-like mass, and he lists among their qualities that “they are not hygroscopic, do not absorb water, and only slightly weigh down the foundations of the structures”.

At the time of the Ancient Romans pumice was largely used in the construction of thermal baths and temples, many of which can still be seen today.   The two most notable examples from these times are the Pantheon of Rome, where granules of pumice were used in the construction of the dome, and the St Sophia Cathedral built by the Byzantines in Istanbul in the Forth Century AD.

From this time until the 1800’s when the use of pumice reappeared in many Rhinenland cities in Germany, it seems that the use of pumice in construction was disregarded in Europe. In the USA Pumice began to be used in the construction industry in California in 1851, and expanded into 15 states and 103 workplaces.  Currently, with the development of technology and increased awareness of environmental issues its uses have spread into many other diverse industries.

Our Pumice Solution For You

Pumice Powders and Grains


Volcanic Lightweight material/ lightweight substrate


Cosmetics, PCB Boards, Polishes, Dental

TDS (Technical Data Sheet)

Pumice Lumps


Volcanic Lightweight material/ lightweight substrate



TDS (Technical Data Sheet)

Pumice Aggregate


Volcanic Lightweight material/ lightweight substrate


Construction, Green roof systems

TDS (Technical Data Sheet)

Pumice Blocks


Volcanic Lightweight material/ lightweight substrate


Masonry applications

TDS (Technical Data Sheet)
Ben Salt

For further information please contact:

Mr Ben Salt, Pumice Product Manager

Tel: 01782 409513

Email: ben.salt@rbhltd.com

Or Complete the Form

Name (required)

Position (required)

Organisation (required)

Nature of Business


Phone (required)


Email (required)