Here's a photo taken from a distance...
...and here's a close-up.
What happened to the stone in the necklace? Well, as the classic saying goes, "That's not a bug; that's a feature". From a comment on JIRA entry VWR-13868:
The large number of highly detailed sculpties has exceeded a recently added limit on the maximum number of vertices that the rendering engine will process. When the limit is exceeded, the renderer stops rendering any later vertices. The skip vertices could be from the same object or any other object in the scene.That explains both the flickering buildings and the vanishing jewelry. It's a rather blunt instrument, as the commenter (Street Spotter, and thank you if you're reading this!) points out in the last sentence quoted, and that's unfortunate. if the choice is forced on me, I think I'd rather have some of my jewelry disappear than parts of buildings.
There's a workaround of sorts, though as a fixed setting, there will always be some scene that will force the problem:
The workaround for this problem is to reduce the number of high resolution scrulpties [sic], or to adjust one of the debug settings "renderMaxNodeSize". The default value of 4096 for renderMaxNodeSize causes some portions of [a necklace that displays the bug] to disappear when zoomed. Incresing [sic] this value above 6000 displayed all the elements of the necklace.SL jewelers are understandably highly upset--but it's not just them. Q Linden says "Occasionally, imposing such limits will break a tiny fraction of existing content", but I question whether the content broken by this can be fairly characterized thus.
P.S. If you look at the full-size version of the first photo, it will be obvious that the stray spots on photos are back. Sigh.