In a recently published study on synthetic emeralds grown by Prof. R. Nacken (K. Schmetzer et al., Winter 2016 G&G, pp. 368–392), three different types of flux-grown crystals and faceted samples were described. The vast majority of the synthetic emeralds, comprising several hundred samples, fell within two groups designated types 1 and 2. Most of these had been obtained either from a parcel donated by Nacken to the Deutsches Museum in Munich or from material that had remained in Nacken’s family and was now in the possession of his grandsons. Upon examination, all crystals and faceted samples of types 1 and 2 were found to contain irregularly shaped seeds of colorless beryl. In contrast, only a few synthetic emeralds of another type, designated type 3, were discovered. These lacked colorless seeds and had come from the collection of the late F.H Pough, who in turn had acquired the crystals from G.O. Wild. Existing documentation shows that Wild possessed a parcel of Nacken synthetic emeralds during the period after 1945 and donated various samples to friends and colleagues for research and related purposes.
In 1936, the German government decided to affiliate the private Institute for Gemstone Research, located in Idar-Oberstein and directed by G.O. Wild, with the University of Frankfurt. Nacken was named director of the joint entity, with Wild remaining the local leader for activities in Idar-Oberstein. A close collaboration between Wild and Nacken during 1936 and 1937 has long been apparent from known writings, but no direct information about the synthetic emeralds in Wild’s possession has previously been available. Wild’s son, K.E. Wild, had seen the parcel with Nacken synthetic emeralds in the 1950s and 1960s, while working in his father’s office, but no further background about those samples was given to him at the time (K.E. Wild, pers. comms., 2016, 2017).
A new development, however, serves to unveil further details. A document authored by Nacken and dated May 30, 1937, was recently found in the historical archive of the city of Idar-Oberstein (Stadtarchiv Idar-Oberstein, Department 2b, File I B, No. 94). The four-page summary, written to the head of the local administration for the District of Birkenfeld, reports goals and tasks of the Institute for Gemstone Research. In the section covering scientific research, the following is written (translated from German): “Examination of properties related to crystal growth and synthesis of gemstones. These experiments already resulted in the production of synthetic emeralds.”
From this short statement, it becomes apparent that growth of synthetic gem materials was one of the specific research topics undertaken or at least planned at the Institute. Equally logical then is the corollary that Wild, being the local representative in Idar-Oberstein, would have had access to the synthetic materials grown in relation to the Institute’s research projects. Although no additional information is provided in Nacken’s report, the timing would support a conclusion that at least some experiments related to the growth of synthetic emeralds were performed in the 1930s, with Nacken attempting to improve the technique by which he had successfully synthesized emeralds in the 1920s. Presumably, he would have tried to avoid larger colorless zones within the synthetic crystals, as such areas are easily observable, especially in faceted samples. Thus, taking into account all known circumstances, current evidence would seem to suggest that Nacken’s type 3 flux-grown synthetic emeralds without colorless seeds were a result of experiments performed in the 1930s, subsequent to the growth of type 1 and type 2 synthetic emeralds with colorless seeds in the 1920s.
Karl Schmetzer
Petershausen, Germany
In a recently published study on synthetic emeralds grown by Prof. R. Nacken (K. Schmetzer et al., Winter 2016 G&G, pp. 368–392), three different types of flux-grown crystals and faceted samples were described. The vast majority of the synthetic emeralds, comprising several hundred samples, fell within two groups designated types 1 and 2. Most of these had been obtained either from a parcel donated by Nacken to the Deutsches Museum in Munich or from material that had remained in Nacken’s family and was now in the possession of his grandsons. Upon examination, all crystals and faceted samples of types 1 and 2 were found to contain irregularly shaped seeds of colorless beryl. In contrast, only a few synthetic emeralds of another type, designated type 3, were discovered. These lacked colorless seeds and had come from the collection of the late F.H Pough, who in turn had acquired the crystals from G.O. Wild. Existing documentation shows that Wild possessed a parcel of Nacken synthetic emeralds during the period after 1945 and donated various samples to friends and colleagues for research and related purposes.
In 1936, the German government decided to affiliate the private Institute for Gemstone Research, located in Idar-Oberstein and directed by G.O. Wild, with the University of Frankfurt. Nacken was named director of the joint entity, with Wild remaining the local leader for activities in Idar-Oberstein. A close collaboration between Wild and Nacken during 1936 and 1937 has long been apparent from known writings, but no direct information about the synthetic emeralds in Wild’s possession has previously been available. Wild’s son, K.E. Wild, had seen the parcel with Nacken synthetic emeralds in the 1950s and 1960s, while working in his father’s office, but no further background about those samples was given to him at the time (K.E. Wild, pers. comms., 2016, 2017).
A new development, however, serves to unveil further details. A document authored by Nacken and dated May 30, 1937, was recently found in the historical archive of the city of Idar-Oberstein (Stadtarchiv Idar-Oberstein, Department 2b, File I B, No. 94). The four-page summary, written to the head of the local administration for the District of Birkenfeld, reports goals and tasks of the Institute for Gemstone Research. In the section covering scientific research, the following is written (translated from German): “Examination of properties related to crystal growth and synthesis of gemstones. These experiments already resulted in the production of synthetic emeralds.”
From this short statement, it becomes apparent that growth of synthetic gem materials was one of the specific research topics undertaken or at least planned at the Institute. Equally logical then is the corollary that Wild, being the local representative in Idar-Oberstein, would have had access to the synthetic materials grown in relation to the Institute’s research projects. Although no additional information is provided in Nacken’s report, the timing would support a conclusion that at least some experiments related to the growth of synthetic emeralds were performed in the 1930s, with Nacken attempting to improve the technique by which he had successfully synthesized emeralds in the 1920s. Presumably, he would have tried to avoid larger colorless zones within the synthetic crystals, as such areas are easily observable, especially in faceted samples. Thus, taking into account all known circumstances, current evidence would seem to suggest that Nacken’s type 3 flux-grown synthetic emeralds without colorless seeds were a result of experiments performed in the 1930s, subsequent to the growth of type 1 and type 2 synthetic emeralds with colorless seeds in the 1920s.
Karl Schmetzer
Petershausen, Germany
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