It seems I am doing something wrong when I'm cleaning rocks with crystals. The latest was today, found this beautiful gastropod that just sparkled brilliantly with tiny crystals. All I did was pour rainwater over it to wash away dirt from some of the other fossils on the rock and the sparkle is now gone. It seems like just getting the crystals wet with either my well water or rainwater makes the crystals loose some or all of their sparkle. I can leave it out in the rain, such as what's happened with the purple druzy crystal and shells in second picture and that's fine - they sparkle brilliantly. Is there something I can do to repair this or at least something I can do differently to clean new finds?
Thank you