Dear colleagues, has somebody an idea what this can be? These are spheroidal prickly figures (diameter less than 1mm), which are arranged rare single, mostly in groups. Here you can see it in the frontal sinus of a human Os frontale.
My first guess was fungal perhaps? Black lichen? What is the provenance of the bone?
Having ruled out Constantine's suggestions, another possibility is manganese crystallization. Put a drop of bleach on them. If they are degraded, then it is organic, if not, it is crystalline.
Tim
Depending on the soil conditions (and if not fungal/bacterial), my best bet would also be manganese (Mn), as these are also found as black spherules in soils. Their spikey nature however, hints at a biological nature.
I agree with Basak. Manganese and Arnoldussen. Manganese stains are not spikey and do no show any particular organization. This structrure is suggests a biological nature.
Using bleach is a good idea to test its nature, however (out of conservation sake) I suggest you collect a sample to a class dish and test it not directly onto the bone.
Best,
Claudia
Lichens substitute in manganese oxide. That may be worth investigating further. We have had this experience on fossil bones from South African cave sites.
Dear colleagues,
Thank you very much for the many replies. I had already assumed - and hoping that it is not true - that it is mold.
Dear Constantine, the bones come from a medieval to early modern cemetery in Berlin. The bones were dry cleaned, they were not washed.
Hi Timothy, thanks for the tip with the bleach and thank you Claudia for the tip with the glass dish!
Manganese we had already suspected, but I personally unlikely because the black point are soft and fluffy, with manganese they need to be fixed.
Next week, I will start the experiment with bleach and then I inform you about that result.
Thank you very much again to everybody!
Best wishes Barbara
Dear Barbara, dear colleague,
I think that it is a kind of mold that results from improper storage bones. I met with those in old museum collections. The best offer for this subsequent article says:
1) http://bone-lust.blogspot.cz/2013/06
2) http://www.biotopia.net.au/gpage.html
I hope this has helped you. I wish every success!
Best regards,
Milos
- Badges
- Science topic
- Similar topics
- Geoscience
- Cartography
- Mapping