I realized the lead pencil was invented fairly recently (18th century), what did people, specially artists, use before then? I'm certain I've seen many earlier art pieces that seem to have been done by some sort of pencil. If someone could tell me more about writing and painting utencils in general I'd really apreciate it.
The drawing implement that I think looks *most* like graphite pencil is probably silverpoint; this was used by artists and scribes throughout the Middle Ages and Renaissance. Silverpoint is basically just drawing using a thin silver wire or rod. While it can be used on unprepared paper it was more commonly used on paper that had been coated with gesso (a mix of a sort of glue and chalk). The line left by dragging the silverpoint across the gesso-coated paper (or panel) is a very faint grey that will then oxidize over time (although in my own tests with silverpoint I'm not sure I've had them long enough to watch this change firsthand).
Leonardo da Vinci is notable for some especially beautiful silverpoint drawings, such as his Bust of a Warrior.
And you can see an example of an artist using silverpoint in Rogier van der Weyden's Saint Luke Drawing the Virgin (see the detail photos, in particular, to see what the silverpoint tool looks like).
One thing to note is that while silverpoint can look like graphite pencil it can't be used in entirely the same way as graphite pencils. Pressing hard with silverpoint won't really get you a darker line, as it would with a graphite pencil. To build up areas of darker tone you need to draw and layer repeated lines, and even then you aren't ever going to get a line that is as dark as a soft graphite pencil. Silverpoint also doesn't smudge or blend in the same way that graphite (especially softer graphite) will. Nor is it easily erased, although you could scrape away marks with a blade.
It's also worth mentioning that silverpoint wasn't the only metal used for drawing: lead and gold were also used. But in my experience (primarily drawings from the Middle Ages and Renaissance in Italy and Northern Europe), silverpoint is by far the more common metal.
The other drawing material that can look like graphite pencil is black chalk. A drawing like Michelangelo's Pietà is an especially fine example of the range of tonal possibilities using black chalk. Using chalk (which also is available in shades of red and white) is somewhat more similar to how a graphite pencil works: i.e., applying more pressure will give you a darker line, repeated strokes can help you build up very deep blacks, and you can smudge and blend the marks for a variety of effects.
As another user mentioned, charcoal is another option that can look like graphite pencil. Leonardo's Virgin and Child with Saint Anne and Saint John the Baptist is an example of a charcoal drawing (heightened in places with white chalk). Charcoal was also used for preparatory drawings and sketches on panels and canvases before applying paint (although the other media mentioned previously could also be used).
Any and all of these materials could be used for writing, as well. Materials might also be combined in single drawings: e.g., it was common to use white chalk to highlight drawings that had been done in silverpoint, black or red chalk, or charcoal. Pen and ink was also quite common, but your question was focused on materials that look like graphite pencils, and ink drawings generally have a very different look.
This is mostly sourced from my own knowledge and teaching, but if you need bibliography on Renaissance drawings I can dig them up.
You’re probably thinking of charcoal drawings.
“Charcoal has remained a popular medium for drawing since the Renaissance. At that time, it was used for preparatory purposes: to develop initial ideas, preliminary outlines, areas of shadow, or for squaring grids used to transfer a design to another surface.”