This heat sinking method requires a coffee grinder and a 1 foot square ceiling tile that I bought at Lowes or Home Depot. 

This is the stock number... on the tile. 

Next, break off some small pieces and put them in the coffee grinder and hit the switch and break the pieces down to fibers like this. 

Next, find a metal lid (metal is important because of the heat) and put the fibers in like this. 

Once you add water, it'll look like this . 

This Garnet ring won't take heat so it's a prime candidate for heat sinking.
 

Simply bury the stone into the heat sink and solder.  The real trick is once you've finished your soldering, immediatley lay the entire ring over into the heat sink to cool it before any more heat transfers towards your stone.  The one thing that makes this method better than any other I've tried is the mud compound has structural integrity.  You don't need to use any other mechanical holding devices or soldering tweezers to hold or balance the item you are soldering.  Just bury it and move it where ever you need it and solder away.

When you're not using it, just set it aside and it will dry out.  When you need it again, just add water and you're back in business.  It never goes bad, and it never smells...so...everyone is probably wondering why it's called 'Magic Baby Poo'.  Once the metal in the lid begins to rust over the years, the rust changes the color and click here to see what it looks like after a year or so....