It will not be possible to visually identify those pebbles. Natrolite, Mesolite, and thomsonite are all very similar. The best way to id them is with optics. Often all three or a combination of any two of them will be found in the same crystal. Rudy Tschernich has illustration of such zoned crystals in his Zeolites of the World. Where did you collect these?
From Doug Merson - January 16, 2012 at 07:18:55