Study and report of a unicum gilded ceramic statuette
of Aphrodite using Thermoluminescence, Infrared and Xray Spectroscopy
Client: Benaki Museum
The authenticity of a unique and undocumented golden statuette
of Aphrodite from the Hellenistic Collection of the Benaki Museum
was examined by combining microscopic, analytical and dating techniques.
The statuette consists of a coroplastic clay core covered by a gold
layer. The composite nature of the statuette leads to the formulation
of the following three hypotheses: (1) both the core and the gold
layer are ancient and thus the object is authentic, (2) the gold
layer has been applied in modern times on an ancient terracotta
and (3) both core and gold layer are modern and the object is entirely
fake. Examination under the stereoscope revealed a smooth surface
with very few imperfections, scratches or cracks. On the lower front
elevation a square gold patch is visible, however the continuity
of the relief lines across the patch suggest that the whole surface
was covered in a single operation. Moreover the presence of the
patch implies that the surface was covered by a gold leaf technique,
rather than by following an amalgamation procedure. Where measurable
on the base, the thickness of the leaf is about 100-120 µm
(i.e. 0.010-0.012 cm). The overall smoothness of the surface can
be attributed to successive polishing treatments.
Thermoluminescence measurements of the clay core material showed
typical geological doses implying that the core has not been fired
above 350oC. Though this precludes the possibility of dating it
provides a very important clue concerning the question of authenticity,
in view of the fact that unfired clay objects do not retain their
sculptured features following burial. This allows us to exclude
the hypothesis that the object is the result of a modern gilding
on an ancient terracotta.
Non-destructive X-ray Fluorescence analysis of the gold surface
revealed a high quality gold-silver alloy with a low copper content.
Typical percentage by weight is 96.8% gold, 2.8% silver, 0.4% copper.
The absence of lead shows that the gold has not been refined by
removing silver. Similarly, the absence of mercury suggests that
the gold was not obtained by an amalgamation precedure. The composition
of the gold alloy broadly agrees with the analyses of gold artefacts
found in several Hellenistic Macedonean sites (i.e. Sindos, Ag.
Paraskevi, Phoenix). The purity and thickness of the gold layer
account for the excellent conservation of the statuette.
Furthermore, the thickness of the layer clearly exceeds the minimum
required to produce the desired effect. Indeed, from the Middle
Ages onwards the typical thickness of the the gold leaf in gilded
objects is of the order of 0.001-0.0001cm. The total weight of gold
in the Aphrodite statuette is of the order 15gr were as 1-2 gr would
have sufficed to produce the same effect. This generous use of gold
may account for the rarity of similar objects due to the advantages
of recycling the precious metal. A converse argument would suggest
such an unnecessary waste would not be the practice of a modern
faker. The current value of the gold used is about 150 EURO. In
conclusion, the combination of all available evidence suggests that
the golden Aphrodite of the Benaki Museum is not a fake and stongly
supports the conclusion reached independently by prof. A. Delivorias
E. Aloupi, N. Zacharias, A. G. Karydas, The Gold Statuette of Aphrodite:
Problems of authentication in ''The Benaki Museum Journal'' 1, 2001,
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