Kehoe's Agate Shop, Big Fork, MT 06-26-12

Leslie Kehoe owns Kehoe's Agate Shop in Big Fork, MT, an enterprise started by her father years ago near this little artsy town at the north end of Flathead Lake.  I visited the last time I was in Kalispell and was impressed by the stones and articles made of stone.  I purchased a beautiful malachite box.

 
The shop is way off the "beaten track", customers just have to follow the signs to wend their way to the river side location.  Their website is still in progress: http://www.kehoesagateshop.com/

 
 I knew that I would visit again on this trip, so I took a necklace I've owned for almost thirty years and have never be able to find out what it is made of.   I have always called it my stone necklace and I love the primitive look.  It is quite heavy and the stones seem varied, but apparently they are all from the same source, although they don't look at all the same.  I have previously been told they are volcanic, coral, meerschaum, bone and other materials.  I do know that the spacers are heishi shell.  
 

 
Leslie tested a couple of the beads on a spectrometer and checked the results against a book and told me they are a form of opal!  Now I know and can do some more research.  Any comments or ideas are welcome.