I first learned about this type of imitation from an article of Orestes Zervos written in 2002. He notes even though a dozen examples were found in the Cornith excavations only two were known of today, one in Dumbarton Oakes and the other in Cornith Collection. If the article is still accurate, mine would be a 3rd known. The coin is a mix over two Alexius I issues. It has a Christ with gospels Obverse ( SBCV-1929) and an Alexius Jeweled cross( sbcv-1931) . The two issues Dr. Zervos noted were in much better condition than mine and much heavier in weight 4.94 and 3.55gm My new example is much lighter than the other two examples. More equivalent to a half tetarteron. 18.23mm and .9gm Here are examples of the coins the coin was imitating and became a mule. and If you have a Mule or an imitation of any time period feel free to share.