Do keep in mind that the gold market is the same as the diamond. Controlled by a few players and there is no limit to how much can be made available on notice.
Gold is a world market it always hold value no mater how trade markets do.
Diamond are controlled by a few players but never gold.
The only true source of safety is Physical gold in your home safe or buried under the basement
If GLD is paper its worthless...expect a short squeeze as people want physical gold and there isn't any available.