If you search for something like royal aventurine our board will show post results for either word, which you probably did not want.
If you want to search for both, there will be a link under your search that contains AND in it, so you just click that to see posts that contain the words royal and aventurine in them.
There are other links too which will help you narrow the results.
Finally, if you click on the magnifier icon in the search area, you will be taken to the advanced search page where you can fine tune your searches.
Further discussion: I can change the board's default behavior to search BOTH instead of EITHER, but I would need member feedback to decide whether to change that behavior. I assume if I do that, the link logic above will allow you to search for either.