Gyali is a Greek island in the Dodecanese archipelago in the eastern Aegean Sea (36° 40' N, 27° 7' E).

About 200,000 years ago a volcanic eruption occurred on the neighbouring island of Nysiros. During the eruption large amounts of hot pumice were thrown into the sea. The sea water suddenly caused the pumice to cool down, changing its structure and giving it its unique pozzolanic properties. Later, the sea bed rose and the island of Gyali was created, with one of the largest pumice deposits in the western hemisphere.


The island of Giali has a surface area of about 4.5 km² and consists of two hills connected to each other. The approx. 150 m high hill in the southwest of the island consists mainly of pure pumice. In total, there is currently a deposit of around 100 million tonnes of YALI® of the purest quality.

The Quarry

The pumice deposit on the island of Gyali amounts to about 100 million tons and is the largest deposit of pumice in Greece. Currently the annual production rate averages at 1 million tons.

In the case of steady production, the YALI® deposit will be available beyond the year 2100.

Disassembly and Loading

Yali® is mined in opencast mining without explosives with bulldozers. The bulldozers push the pumice stone from the mountain onto an automatic conveyor belt system, which transports the pumice stone to a separation plant.

In the separation plant the pumice is screened into different grain sizes, which are stored separately on large storage areas.

From the warehouse, the pumice is loaded by conveyor belt with a loading rate of approx. 1,000.00 MTS per hour directly into seagoing vessels up to 26,000.00 MTS.

The storage capacity of several 100,000 MTS and the shipment in large ocean-going vessel units make it possible to ship YALI® in a short time with consistent quality and thus also to provide it for large projects.

LAVA Mining & Quarrying Co.

Yali® is mined in the pumice mine on the island of Gyali, located in the Dodecanese of the Aegean Sea between the islands of Kos and Nysiros.

The mine is operated by LAVA Mining & Quarrying Co, a subsidiary of LafargeHolcim, one of the largest cement producers in the world.

Yali® is mined in the mine in open pit, screened into different grain sizes, prepared for transport and shipped by ocean-going vessel to the countries of destination.

LAVA Mining & Quarrying Co. works according to the highest quality standards within a certified and externally monitored production process, thus ensuring a consistent and high-quality production of the various YALI® grain sizes.


The quality of YALI® remained constant over the last 30 years due to the homogeneity of the deposit on Gyali Island. The production of various graining, the possibility of mixing them freely and large stocks available all year round ensure high flexibility and efficiency of the certified production of the quarry.

Please find EN, ASTM and CE-certificates here.


is an organically and inorganically pure natural material,

  • and thus very environment-friendly,
  • has a low volume weight,
  • has excellent insulating properties,
  • has sound deadening properties,
  • is fire resistant,
  • has excellent mechanical strength,
  • has consistent white color, and
  • is homogeneous of quality.

The Yali® product range includes the grain compositions listed below. These are the most common and most used grain sizes. Yali® is produced in these basic grain sizes on Gyali and stored for transport.

The different grain sizes can be mixed with each other as required to meet your specific needs. We would be happy to work out an individually tailored recipe with you.

Fine YALI®, sand-like, which is ideal for the production of white, lime-bonded thermal insulation blocks with a smooth surface, as well as mortar and fine plaster.  

Due to its low fine content, < 1mm, this grain size is easy to mix with other materials.

YALI® with a granular content for the production of cement-bound pumice building materials, which is also ideally suited for the production of mortar and structured fine plaster.

YALI® - grain of medium size with low fine content, which is particularly suitable for the production of lightweight concrete elements and other cement-bound pumice building materials and can be used very well for green roofs, for the renovation of cellars and for the insulation of attics.  

YALI®, uniformly screened with low grain density and high grain strength, which can be used above all for refining cement-bound pumice building materials, for green roofs and for damp and poorly load-bearing subsoils in road and path construction as well as in sports and golf course construction. 

Average chemical composition

SilicaSiO271,97 %
AluminaAl2O312,66 %
Ferric OxideFe2O31,13 %
LimeCaO1,46 %

0,32 %

Sulphuric OxideSO30,03 %
Potassium OxideK2O4,30 %
Natrium OxideNa2O3,45 %
Loss on ignition  4,53 %
Undetermined 0,21 %

100 %


Here you will find:

Tests and measured values for YALI®.

Tests and measured values for YALI® products.


  • CE-certificate for YALI® 0-3 mm
  • CE-certificate for YALI® 0-4 mm
  • CE-certificate for YALI® 0-6 mm
  • CE-certificate for YALI® 0-8 mm
  • CE-certificate for YALI® 2-10 mm
  • CE-certificate for YALI® 0-16 mm
  • CE-certificate for YALI® 0-16 mm Landfill
  • CE-certificate for YALI® 0-40 mm Landfill


YALI® is available in large quantities and in consistent quality. The homogeneous deposit on the island of Giali, the different grain sizes, the possibility to mix them according to the customer's needs and the year-round availability result in high flexibility and efficiency of the certified production on the island of Gyali.

Please find EN, ASTM and CE-certificates here.


is a natural raw material

  •     without organic and inorganic impurities,
  •     very environmentally friendly due to low CO² emission during mining and transport
  •     has a low specific weight,
  •     has excellent insulating properties,
  •     has sound-insulating properties,
  •     is fireproof,
  •     is frost-resistant,
  •     has excellent mechanical strength,
  •     a uniform white colour, and
  •     a uniform quality.


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