Question: I have a large ceramic soup cup which appears to be internally damaged after being rinsed with cold water while hot:

![Ceramic cup with visible cracks throughout](https://i.stack.imgur.com/kj0v8.jpg)

Is this cup still safe to use, or is it likely to shatter or otherwise fail during use?

Answer: 
Looks [crazed](https://www.google.com/search?q=crazed%20ceramic&safe=off&client=firefox-a&hs=2QS&rls=org.mozilla%3aen-US%3aofficial&tbm=isch&tbo=u&source=univ&sa=X&ei=7fXBUo6bAo7AkQeW1oCACQ&ved=0CE4QsAQ&biw=1478&bih=783). Sometimes that's a death sentence for a cup, more often it means that dark colored liquids can seep into the cracks, and make things look interesting. Sometimes not even that happens, and you just have a cup with an interesting pattern in the glaze.
Cracks in any dishes hold bacteria so they are always unsafe. Never use dishes with any cracks in them for food. Chips on edges of plates or serving dishes do not really present a problem, but all tiny cracks present a health problem and the poster is also exactly right about leaching into the cracks and molds and staining resulting. If dishes have any cracks, even tiny crazing, you should think of them as unsafe for foods and eating, any kind of foods, even dry foods. And what is unsafe for humans is also unsafe for your pets. Bacteria that you do not know about can be deadly. That is why it is important for human animals and pet animals to eat cooked foods.