So here’s an interesting thing! In Xania there were numerous shops selling blue and silver jewellery like this, as if it were a Cretan specialty.

I kept wondering what kind of stone it was and kept coming back to opal, but opal is Australian, right? And then I saw a brooch that was a kangaroo! I had to ask, and sure enough it was opal all the way from Australia. Someone must have decided that the blue was so evocative of Crete (and it absolutely is) that people in quantity would buy it. And I guess if it does good things for you, why not?