At the begining during a travel in Cappadocia, I bought five eggs to an artisan of Mustapha-Pacha, because it was one of the cheapest souvenir, and I want to bring one. Later in french guyana, it's the first wooden eggs of amazonia: I would like to bring a part of this wonderful forest.
So I started this collection, which costed not too much, of objects so representative of visited countries.
Then, it was the eggstone of Madagascar, and in the south of Morroco (in Atlas range)... and so, at each trip, I try to bring a part of the country in forms of wooden or stone eggs (depending of the country speciality). It's quite easy to find eggs of minerals (unfortunately, often in an anonym onyx, and mass-producted in India, Egypt or Mexico ! and sometimes garishly coloured without no relation with the original).
It's much more difficult to find wooden eggs.
And yet, what's easiest to turn a piece of wood, even at an hand-craft manner ! Is it a aera in the world which own no wood species to emphasize ? But don't kill a tree for this, just take a part w/o killing : it must stay a renewable material.
For the same reason, and because I did not got any eggs of my own regions - Lorraine and Normandy - , I start to turn some, And I encourage people do do similar.

Presenting a natural material, the polished and varnishing eggs represent a finish object, with simple shape, more esthetic for collection than rough sample of wood (although some are of the opinion that the wood polishing or varnishing, hide the real natual texture).
An egg shape show in one time each face of a so non homogenious materiel as wood: sapwood, heartwood, edge face.