Eskisehir meerschaum

Meerschaum is German for sea foam, and the name is not poetic licence. The mineral is sepiolite, a magnesium phyllosilicate with the formula Mg4Si6O15(OH)2 six-water, and its specific gravity runs from about 0.99 to 1.28, which means a porous block of it will float. Fishermen used to find lumps washed up and assumed the sea had made them. The mineralogical name comes from Greek instead, sepion for cuttlebone, because that is what it looks like.

It is soft. Mohs 2, scratchable with a fingernail, which is exactly why it became the world's carving stone for pipes rather than a gemstone. Turkish calls it lületaşı, pipe stone.

The world's largest known reserves sit under the plain of Eskişehir, between Istanbul and Ankara, and the way it is worked there is remarkable. There are about four thousand shafts on that plain leading to horizontal galleries, dug to follow lumps of sepiolite through the clay. Not an open pit. Four thousand small holes in the ground, worked by hand, in villages that have done nothing else for generations. The trade called the material white gold long before anyone was marketing it.

Sepiolite forms as a secondary mineral around serpentine and precipitates in arid settings, which is why it turns up with dolomite and opal.

The reason smokers pay for it is the porosity. The stone pulls moisture and tar out of the smoke and into itself, and as it does the pipe changes colour from the base upward, through yellow and orange to red and amber. A well smoked meerschaum is a record of its own use.

You cannot go and dig here. These are working private and village-held claims in an established industry. What you can do is go to the Eskişehir Meerschaum Museum and see what a carver does with a block of floating stone, which is the better half of the story anyway.