Ok, so I just baked this sucker. Diamonique stones/epiphany (plat over silver). Here is what I did.
1. Cleaned thoroughly with toothbrush, dish soap and a small capful of ammonia then dried and polished.
2. Put in a pyrex dish and added to a cold oven to go through the preheat process so it could slowly come up to temp. Baked at 400 degrees for 2hrs. Turned off oven and left inside to slowly come back down to normal temp on its own.
Here's our before/after shots... The change doesn't show up as much in photos but looks so much better to my eyes. I do notice more of a steely look to the center stone but the baguettes are sooo much better. Think I might give it another go and see what happens.
LEFT:BEFORE RIGHT:AFTER