Portrait of Cecilia Gallerani or "Lady with an ermine" and detail of the necklace
Cecilia Gallerani, the famous Lady with an Ermine portrayed by Leonardo da Vinci at the end of the 1400s (perhaps 1498), she can be taken as the model of a typical "fashionable" Milanese girl of the time.
The girl, who was about fifteen at the time of the painting, shows herself with a hairstyle then in vogue (https://www.pilloledistoria.it/8127/storia-moderna/400-la-bella-acconciatura-della-dama-con-lermellino) and with only one jewel (synonymous with greater sobriety and refinement than many contemporary ladies of hers accustomed to dressing up in a decidedly more showy way).
Cecilia's thin and white neck is surrounded by a necklace tightened around her throat and then left to hang on her breast, as many other girls of her age used to do at that time, who were also unmarried, but the material of the jewel remains a mystery to this day.
What were the black beads that make up the necklace made of that centuries later we can still admire wearing at Gallerani?
Various hypotheses:black amber, onyx, black coral and agate are the most accredited.
However, there is also another, rather plausible one, according to which it would instead have been simple fragrant paste grains , for which it broke out, in full Renaissance , a real craze on the part of men and women.