I have been trying to sell an emerald, but every time I talk to any storekeeper, the emerald doesn't show up in my items I am able to sell. It was stolen and I thought that might affect it, but I have previously sold two amethysts that I got from the same place. What is wrong?
stolen flag is something that can be affected by player relationships to NPCs before taking a thing. Joining a faction will make their items "normal" instead of "hot" if you take them, most of the time. You can also take from friends. In both cases, your relationship is checked for this flag; items that are of particularly high value are usually still marked as "stolen" if taken, as they are usually not things to which the player is welcome.
Ex. Runs-From-Responsibility is a Saxhleel (Argonian) that is way behind on child support, but has a drawer with jewels in his house. In it are two
Amethysts and a
Flawless Diamond (or, mod depending, 1 carat Amethysts and a 30 carat Diamond). You
speechcraft his way out of his child support debt (you monster) and he considers you enough of a friend to let you take the Amethysts but taking the Diamond would still be flagged as stolen. He gives you a quest to set fire to his ex-wife's house with everyone inside (you monster) and you do it (you absolute brigand). Now he likes you enough that you can take the Diamond and it not count as a stolen item.
This is easy to overlook in situations where there's a bowl full of gems or things of varying value on a shelf.