In Hilbersdorf, a part of Chemnitz city, it is possible to find some of the highly desired “Star-Rocks”, while construction-work is running. These rocks are a special kind of petrified wood - the outer parts of the rim of Psaronius-ferns from permian age. These parts are consisting of former hollow, now silificied channels. Sometimes these roots are not only silificied but they are agatized. In a first class collectors specimen hundreds of little fortification agates - each different to the other - are visible on the polished surface of the log.
More information about this locality is given from Reiner Haake in his book : “Achate sammeln in Deutschland, Teil 1”, Bode Verlag, 2000.