Beautiful, Sergio!
Absolutely masterful handling of the medium and the material. The only work I know that comes close to this in pastel or charcoal are the charcoals of Robert Bechtle, who's primarily known as a photorealist painter. His charcoals are rare, and are hard to find on the internet. I'm including some links, One because it's a French website, and the other becaude it has the only image I could find of one of his charcoals. The image is not very good. I've seen some drawings of his that were interiors, and at least one self-portrait that were really stunning, but I think your work compares quite favorably with his.
http://www.hyperrealism.net/Robert%20Bechttle.htm
http://www.gallerypauleanglim.com/exhib_2002_10.html