I believe that the green ' Skin' of Agates will prove to be celadonite and not delessite, as has been generally supposed." This is an extract from a paper by one of us, which was published in 1879 in the Transactions of the Royal Society of Edinburgh.

Quarrying for agates upon a large scale having been carried out for several weeks during a succession of years on the shore of Forfarshire, an unusual supply of tile soft coating which frequently invests them was obtained.