Warning: don't clean bone artifacts with bleach, learned that in Santa Fe the hard way

I volunteer at a small museum in Santa Fe and we got a box of ancient工具, mostly deer bone awls and scrapers, in for cataloging. One piece had this dark staining I figured was just old dirt, so I soaked it in a weak bleach mix for about 20 minutes. Big mistake, the bone started flaking apart at the edges and the surface turned chalky white where the stain was. My supervisor walked in and just sighed, said bleach dissolves the collagen in old bone and there's no fix once it starts. We ended up having to note it as damaged and store it in a separate drawer with a warning tag. Has anyone else messed up a find with the wrong cleaning solution, and what do you use instead for stubborn mineral deposits?

2 comments

2 Comments

logan_ellis3d ago

Three inches of that chalky mess is all it took for me to learn the same lesson with a mammoth rib fragment at a ranch in Montana. My boss at the time said the same thing about collagen and called it “chemical training wheels” for amateurs like me. The worst part is the flaking starts slow, then you walk away for ten minutes and come back to a pile of prehistoric dust. Distilled water and a soft brush is the only honest answer, even if it means those dark stains stay put forever. I’d rather look at a stained artifact than a destroyed one any day of the week. That warning tag might be the most useful thing in that drawer.

jenny_hall4d ago

Oh man, the chalky white thing hit me right in the gut. I did almost the same thing years ago with an old shell pendant, used vinegar to get rid of some crusty build up, and it just crumbled into sad little pieces in my hand. My buddy who worked at a dig site told me later that he uses diluted hydrogen peroxide for stubborn stuff on bone, but even that can be risky if you leave it too long. Honestly now I just use a soft brush and distilled water and let the mineral deposits be, because every time I try to get clever with chemicals, I end up with a box of labeled regret. The separate drawer with a warning tag is brutal but also really smart, at least future volunteers wont repeat your mistake.