Part-timer here, always like to look at your beautifully preserved specimens! I collected a number of concretions and recently have had some time to hone my prepping skills....Some of the ammonites I am working with have an awesome mother-of-pearl look to their shell which tends to fade, dry and flake over time. What will preserve them? Is there something that I can do to them before air abrasion to avoid fracturing them?
Here's a couple of pics.....my technique has been smash the concretion with a big hammer then look for specimens to work with, is there a better way?