At first glance it looked like charcoal and pencil on paper to me, however, upon closer inspection I'm thinking that might be oil pastel. That rich black looks like oil pastel, and both charcoal and oil pastel are messy and can turn the paper grey like that. I'm leaning towards pastel because of the sort of large, grainy effect of the shading on the bottle, which you can also see in the way the pastel has coated the page. Charcoal, while it also has that grainy effect, tends to be much finer and less blotchy. The light grey on the checked handkerchief was done with either oil pastel, chalk pastel, or a very soft pencil, but not with charcoal. The shading on the flowers in the foreground was done by smearing, using either finger or a cloth/paper towel the artist smeared some of the pastel into the black to get that lighter grey (though the artist did not use that technique for the checks, that was done with a lighter colored implement).