I like mechanical graphite pencils (e.g. 0.5 mm), because they are sharp, they do not contain wood (are eco-friendly and do not generate any waste) and they do not require sharpening which can consume the pastel core as well. And I like pastel pencils because I like drawing small and detailed images. But why there are no best from the both worlds - mechanical pastel pencils? Or maybe there are?

Some 30-40 years ago the Soviet Union existed and I remember that they had mechanical pencils with wider cores, I don't know exactly, but they may have even 1-2mm cores and the cores could be graphite or something similar to colourful chemical pencils (watercolor pencils). I am not sure whether it was mass product and whether they were just exploring the technologies. Well - Soviet Union used lot of such pencils in postal work and so on, they had not printed labels and small-printing, that is why the writing devices should have been made and they did as they could.