Watch List notes:

The Eparch Collection of Roman, Byzantine and Islamic Weights
ISLAMIC WEIGHTS

Anatolia. The Artuqids of Kayfa and Amid. Rukn al-Din Mawdud, 1222-1231 / AH 619-629. 30 Dirham Weight (Bronze, 39x12mm, 125.75 g), a thick, circular commercial-weight. Double-headed eagle with griffin-like heads and stylized wings ending in curlicues. Rev. Plain, with a flat polished surface. Kürkman 104 (same type, but of 12.5 dirhems). A. Mazarakis, "Three Weights," NomXhron 28, 2010, pp. 95-104, fig. A (this piece). Extremely rare. A solid and impressive piece with a very dark, green-red-brown patina. Nearly extremely fine.

From the Eparch Collection, acquired from a private collection in London.
For an extensive discussion of the iconography and the weight standard of this piece, see the article by Mazarakis cited above. When Kürkman presented the specimen in the KMA collection (see p. 49 for a blow-up photograph without commentary) he described it as being the only known example of a weight with a double-headed eagle.