this is the Epifania cartoon, around 1550AD, black chalk on paper. This is only one of two cartoons (from cartone – Italian for large piece of paper) by Michaelangelo.
He touched this up when he was 70 years of age, but he wasn't the painter, this was done by his biographer Ascarno Condivi which is hanging in the Casa Buonarroti in Florence.
but here are some of the close-ups of the cartoon…how utterly exquisite…
truly amazing work.