Greetings! This is in response to Bill Meier's question on the location of the Pyrex CD 122.4 insulators. This one has a black swirly line of "gunk" in it. It was found on Stampede Pass in the Cascade Mountains of Washington state. Not a spectacular piece, but certainly one that was worth dragging home. Not too many modern pieces with stuff in them.....and every time that I spot it on my shelf it reminds me of the great fun that was had by all during those "days of digging" on Stampede!! Enjoy....