New researches on Koson type coinage in the light of XRF analyses

Aurel Vîlcu1,
Bogdan Constantinescu2
1Institute of Archaeology "Vasile Pârvan" - Bucharest, România
2National Institute of Nuclear Physics and Engineering "Horia Hulubei" - Bucharest-Măgurele, România

The results of the analyses performed in 2008 on 30 gold coins of Koson type from the "old" (before 1914, no finding place data) collections of the Coin Room of the Romanian Academy Library and from the Tārsa hoard (pieces kept at the National Bank of Romania) are presented. We analyzed 8 coins with complex (intricate) monogram, 18 coins with simple monogram and 4 coins without monogram. We also added the results of the analyses on 12 Koson type coins (4 pieces from the "old" collections kept at the Institute of Archaeology and 8 pieces from the Tārsa hoard) presented in 2007 at the First International Symposium ARCHAEOMET (A. Vilcu and V. Cojocaru, On the composition of Koson type coinage). All the coins of Koson type analyzed were struck with six dies of obverse and two dies of reverse. We consider that the face with the eagle represents the obverse and the face with the three personages is the reverse.

The Koson type coins' composition was compared with 15 Greek and Roman gold coins issued between IV-I centuries B.C kept in the collections of the Institute of Archaeology and the Coin Room of the Romanian Academy Library: two Philip II type staters, three Alexander type staters (two from the Daeni hoard), six Lysimachus type staters (one from the Daeni hoard), one Athenian stater, three Roman gold coins issued in the second part of the Ist century B.C.

An involution of the fineness for staters issued in the 4th - 1st centuries BC has been confirmed. The Phillip II stater issued at Pella in 340/336-328 BC has the highest fineness (99.8%). The stater of Alexander type from the Daeni hoard issued at Amphipolis in the second part of the 4th Century B.C. has 99.3% as well as the stater of Lysimachus type issued at Lysimachia in the years 297/296-282/281. The stater of Lysimachus type from the Daeni hoard issued at Odessos (280-200 B.C.) has a slightly lower fineness (98.3%). The analyses on the last staters of Lysimachus type issued at Callatis and Tomis in the time of the Mithridatic wars (120-72 B.C) show that their alloy is similar with that of the Koson coins with complex (intricate) monogram from the Tārsa hoard struck with the pair of dies Obverse1-Reverse1 (see M. Dima and D. Ilie, Tezaurul de monede de tip Koson descoperit la Tārsa, com. Bosorod, jud. Hunedoara. Lotul pastrat la Banca Nationala a Romāniei, in Simpozion de numismatica. Chisinau 29 septembrie-2 octombrie 2004, Bucuresti, 2007, p. 35-65). The analyses on the coins of Koson type with simple monogram struck with the pair of dies Obverse6-Reverse2 show that the fineness is different: 91-93%. It is important to precise that the coins struck with the pair of dies Obverse1-Reverse1 are the heavier pieces from the Tārsa hoard. It is need of more analyses on the coins of Koson type with complex and simple monogram for the confirmation.