Moroccan souk ceramics: safe to use?

Hi,

I recently bought several mugs from souks in Marrakesh. I used one for the first time for coffee and, after use, I noticed the glaze had a web-like pattern, which I believe is called 'crazing'. There was also a slight metallic taste to the coffee...

I wanted to use and gift these mugs but I'm now really worried that they're not safe to drink from! Surely they wouldn't sell them in such volumes in the local/tourist market if they weren't safe?

Would appreciate any insight or advice on how I can put my mind at rest (or whether I need to use them for décor only...)

Thanks!