Synthetic Emeralds Grown by Richard Nacken in the Mid-1920s

Synthetic Emeralds Grown by W. Zerfass: Historical Account, Growth Technology and Properties

“…Nonetheless, it is possible that Nacken could have shown Jaeger examples of those flux-grown crystals. (For more details about Nacken's work, see Schmetzer et al, 2016b. ) Feature Article emeralds parallel to the basal faces.…”

“…Certain aspects of IG Farben's process for Igmerald production were published by Espig in the early 1960s, and further information was contained in internal IG Farben reports dated 1930, 1945 and 1946, likewise penned by Espig, that have recently come to light (for details, see Schmetzer et al, 2016a). Nacken himself never published regarding his emerald synthesis, and only fragmentary accounts can be found in Allied government documents generated from 'interviews' with German scientists in 1945 and 1946 by American and British investigators after World War II (for details, see Schmetzer et al, 2016b). Zerfass also did not formally document his work, but unpublished information was disclosed to his son T. Zerfass (reported in this article).…”

“…During a recent re-evaluation of the growth process applied by IG Farben at Bitterfeld and of the properties of Igmeralds (Schmetzer et al, 2016a), the present authors also examined synthetic emeralds grown by R. Nacken in the 1920s (Schmetzer et al, 2016b) and by Zerfass. These investigations were prompted by reports that the Nacken and Zerfass material had been grown by processes similar to those used for Igmeralds and/or that various people or companies involved might have collaborated.…”