But is that drop in trust really from one program? Seems like there could be other local reasons for it. Hard to pin all of that on a single spy trick.

Man, our training guy brought in a burnt pizza to show us what a bad cure looks like.

Yeah, that acid test is the only thing that really works for me with calcite versus quartz in the field. I started carrying a small dropper bottle of vinegar as a quick check before I even pull out the good acid. Saves a ton of time and you don't waste your main supply. Marking the vein with a different color tape in my notes helped too, just a visual cue so I stop second-guessing myself later.