Achaeometrical Research in Hungary II., 1988

PROSPECTING and DATING - Balázs ERDÉLYI: Authenticity research by thermoluminescent method of some works of art with unknown condition of finding from the antique selection of Museum of Fine Arts

Balázs ERDÉLYI AUTHENTICITY RESEARCH BY THERMOLUMINESCENT METHOD OF SOME WORKS OF ART WITH UNKNOWN CONDITION OF FINDING FROM THE ANTIQUE SELECTION OF MUSEUM OF FINE ARTS. Abstract: We have accomplished a termoluminescent research of four art traded works of art of unknown origins from the antiquity collections of the Museum of Fine Arts (Budapest) in order to determine their authenticity. These works of art included a Roman and two etruscan terracotta woman-head statues and an early archaic Etruscan vessel-keeping stand. I. Materials Sample No. 1. (Inventory Number: 73. 3.A) Roman woman-head statue. The presumed time of its manufacturing is the AD 1

st to 2

nd century. Alternatively, it may be a 1920

th century counterfeit. Its material is yellowish terracotta burnt into a brick quality. It is spongy inside, with a wall thickness of 1.0-1.8 cm. A streak with reddish tonality can be seen on the inner side of it presumably as a sequence of unequal heat effect. The place of sampling was on the frontal part of the neck on the fracture directed upwards from below. Sample No. 2. (Inventory Number: T. 63.) Etruscan or Greek woman's head. The presumed time of its manufacturing, based on comparative research in art history, is about 500 B.C. Its raw material is spongious terracotta with a wall thickness of 1.5-2 cm. The place of sampling was on the inner side of the hole on the top of the head. Sample No. 3. (Inventory Number: 71. 13. A) Etruscan (?) woman's head made around 500 B.C. It was sampled on the left shoulder in a direction from below. Sample No. 4. (Inventory Number 81. 72. A) Etruscan, early archaic vessel-keeping stand from the 8th century B.C. Its material is well-levigated, pure ceramics. Methods 1. Sampling, preparatory work Sampling was carried out by drilling in order to minimise destruction. It was shown in sampling experiments by S.J. Fleming, that during the course of drilling the sampled material would heat up to the critical temperature, thus we do not have to reckon with the decrease or cancellation of the archaeological information. (Archaeometry 13,7/ 1971/ 59). During the course of drilling there was an opportunity to obtain very small amounts of material so as not to damage the work of art. The worst situation we faced occurred in the case of the Etruscan vessel-keeping stand where things were pushed to an extreme. Due to the minimal quantity of this sample we had to leave out the preparation phase and use the entire drilled material for the purposes of measurement, without any further reparation. 2. Irradiation, measurement We irradiated the samples by using 60 СО-gamma radiation-source with values of 3 and 6 Gy. As a consequence of the minimal sample-quantity, we could irradiate only 2 pairs of samples as opposed to the usual 3. In the case of TL-measurements we developed essentially new procedures, since our set of instruments was unsuitable for a fine-grained 53