Is an onyx goblet safe to drink from?

Answer 1

Acid drinks including wine will react with the onyx and cause leaching into the drink. I'm not sure if that is harmful, or a useful source of minerals but it certainly spoils the flavour of red wine. I have some Onyx goblets and I have also noticed that some fruit juices become "fizzy" after just a few minutes residence time, which is a bit off putting, and led me to wonder the same thing as you.

I have found very little information on this on the English speaking web but my wife is Russian and we found a lot more about it on Russian language sites, basically corroborating the above, acid and Onyx are not good bed-fellows. One form of Onyx has low levels of naturally occuring radioactive material in it too, I don't know whether this is at a safe level or not or whether goblet makers avoid this type of Onyx. The verbal description of the greeny-white colour and marbled pattern of this kind of Onyx almost exactly fits my goblets, so after I read that I decided they should have more of a decorative than practical role in our house!