Really? Arian arian? :)
Hmm. Normal usage would be arian glas/gleision or arian gwyn/gwynion for silver-coloured coins such as 10p, 20p etc pieces. On the other hand, if you dig up a hoard of real silver coins then arian arian works fine!
Are there any rhymes
Arian glas, arian gwyn. Does that mean the coins were blue or white underneath?