Nice one, Bing. You have a very good son! I think it is Spanish - that "C" is for Cuenca, maybe? This one is close, but the monogram does not match yours exactly, mint mark on wrong side, etc. But it is close: Features Issuer Spain King Philip II (1556-1598) Type Standard circulation coin Years 1566-1598 Value Blanca (1/68) Currency Real (1497-1833) Composition Billon Weight 1 g Diameter 15 mm Thickness 0.6 mm Shape Round (irregular) Orientation Coin alignment ↑↓ Demonetized Yes Number N# 101008 References Cal# 814 https://en.numista.com/catalogue/pieces101008.html
Thanks for the leads and I think I may have found a coin which matches from Omni, Numismatic Forum here https://www.identificacion-numismatica.com/t47666-blanca-de-felipe-ii-cuenca-1566-1576 Spain, Felipe II., Cuenca mint, 1566-1576 AD., Æ Blanca (= 1/2 Maravedí) (14-16 mm / 1,02 g), Obv.:. patriarchal cross - calyx , on both side of a crowned PHILIPPVS monogram - monograma PHILIPPVS coronado entre marcas Cruz patriarcal - Monograma - Cáliz. Rev.: patriarchal cross - C , on both side of a castle with three towers - castillo de tres torres entre marcas Cruz patriarcal - Castillo - C. Cayón 491, 3121 My son just returned to the US from his assignments in Belgium and Poland. He has travelled extensively in Spain over the past 15 or so years.
