There should also be the realization that 'things' aren't going to make someone happy forever, no matter what they cost you. As ddrueding mention, she may not know how to react to a gift like the one you gave. Sometimes a gift that is costly can be hard to accept by anyone.
You're offering nice gestures and only you know what you hope to get from giving someone something nice, or possibly you're altruistic and don't hope for anything from this other than to see her happy. Typically men give women personal gifts like jewelry in hope for them to be happy in exchange for the woman to like the man more or to win affection. I wouldn't give a girl who is just a friend a set of jewelry, otherwise it can be taken with the wrong intentions.
If your intent is to be more than a friend, sometimes the simpler things mean more than a nice set of earnings or necklace. If you were to do something geeky and fun that took time and creativity, she may have a larger reaction than a fine set of jewelry.
Do you know for sure that she received the gift?