SEPIOLITE (Lüle Stone)
Chemical Formula, Mg2SiO3O8.2H2O
Crystal System, Orthorhombic
Crystal Data, Massive; fine fibrous; Mostly compact nodular, earthy or clayey.
Hardness, 2 - 2.5
Specific Weight, 2
Colour and Transparency, White, greyish, yellowish, bluish green or reddish; brownish depending on the organic matter content, nearly opaque.
As a precious stone, sepiolite is a type of tractable, soft and absorptive magnesium silicate stone that changes colours when exposed. Sepiolite is used for the production of the most precious pipes of the world and the province of Eskişehir hosts the most abundant reserve that is also most suitable for extraction for this stone.
The Sepiolite is extracted under rather difficult conditions from mineshafts extending 1 meter to 140-150 meters underground. Also known as Eskişehir or Oltu stone, sepiolite is white in colour and its desired properties are nonporous texture and lightness in weight. Good quality stones are extracted from soils referred to as ‘Gray’ (Boz) and ‘Camel’s Hair’ (Deve Tüyü).
Sepiolite is ranked on the basis of size and the type of object for carving is designated. The outer surface of the stone is cleaned with a chisel. Imperfections are removed with a ‘Crude Blade’ and the stone is carved as appropriate for the designated object.
As a wholly original material with its elegant and fragile structure, the use of sepiolite is no longer limited to the making of tobacco consumption tools and it is now used also to create brand new works of great practical and aesthetic value.
Upon its extraction from underground, the sepiolite can be easily carved as long as its humidity content is not compromised. The number of blades and similar tools generally produced by masters themselves sometimes reach fifty. In long-term works, in case of loss of humidity and resulting hardening, the stone can be submersed in water to restore malleability. Due to the gradual diminishment of the stone in the nature, care is taken to exploit the material with the least wastage possible.
As for designs, the most important sources are observation and the imagination of masters. The sepiolite carved in the desired manner is then dried for extended durations under indirect heat and finely papered.
The finished sepiolite works are submersed into bleached and sufficiently heated wax to enable the stone to regurgitate imperfections and obtain an ivory colour. Having absorbed the hot wax, the sepiolite is rubbed and polished. In the meanwhile, the sepiolite gains a creamy/yellow colour with an ivory-like appearance.