But once you've read a few chapters, you will note that slowly something of a "big picture" is about to emerge. 37 - Quarz Christian Weise Verlag, München, 2009 ISSN 0945-8492 Johann Zenz Achate / Agates Bode Verlag Gmb H, Haltern, 2005 ISBN 3-925094-85-7 C. Bornträger, Berlin, Stuttgart, 1977 ISBN 3-443-15019-5 R.