[Spoilers Production] Ryan Condal teasing that an item mentioned multiple times in the books will appear for the first time in HOTD S3

While talking on his podcast about the props being built for House of the Dragon season 3, Ryan Condal had this to say about one specific prop:

We have some very specific things we have to build, and one of them is a very inworld thing that we've heard a lot about over from the text of the books, but we haven't really ever seen on screen in a specific way. It's a smaller detail, it's not a big thing, but I just thought it was cool. It's one of those things where you just have to go read all the little snippets that are in the books and you try to put the thing together, take all the information you have and then connect dots as best you can and then fill in the rest. So excited to see that come along, it's a fun one.

Here's the link to the podcast, he starts talking about it at around 14:50.

So a prop that isn't too important for the plot but was mentioned multiple times in the books and hasn't appeared yet on TV, if anyone has any idea what that could be.

Since Oldtown will seemingly be featured more in season 3 I'm thinking about something from there, maybe a glass candle?