My fire was sparkling and I got a villager to put more firewood on the fire (this was before i read the guide). Now my sparkle is gone. Have I missed it for good? What is the best thing to do? Let the fire go out? Or just keep putting firewood on the fire?

No, in fact, it took a few times before the gem appeared for me. Just light it and let it go out again. Eventually, you should get the puzzle.

You don't have to let it go out; you could put it out instead.

How do you get the diamond out og the fire, the people say it's too hot.

Maybe you need to do something to cool it off? You can always check the VV3 Guides if you need the solution.

What is a good thing to cool down something hot?

OK, my fire has gone out twice and still no little sparkling gem. Dose something specific have to happen to make it appear? I read the guide and it didn't mention anything in particular.

There is a comment about not having to wait on fire to go out you can make it go out. I tried that but can't figure it out. Anyone want to share? I really don't want to wait another 10+ hours to solve the puzzle!

The fire won't produce a gem in a short period of time. It takes awhile. Just keep your fire burning, and you'll know when the time is right.

The guide was in error about how long it takes. I'm going to replace them with new ones.

Thanks! Back to the waiting and watching game and I will re-read the guide a little later!

is there a way to put the fire out?

Yes, when the time is right.