Today on Skyrim I dropped a ton of gems into a inactivatable display case, but when I tried to close it, my game crashed.?

That's not a question. That's a statement with a question mark incorrectly added to the end of it.

Yes, if you try to display too many items in one location, it will crash the game. I had this problem in Proudspire Manor, in Solitude. I had vats of gems in the basement, and lots of other items on display, and every time I would go down to use the alchemy or enchanting tables, my game would lag, freeze or crash. I ended up storing most of the gems, instead, and the problem stopped.