Going back to an earlier point, when the graphite was discovered the English thought they had unearthed a lead deposit, a misunderstanding caused because lead and graphite look uncannily similar in their natural form. It is because of this prevailing thought that the pencil was known as the lead pencil, a name that has endured until today.
However, in the Roman times, styluses were used for writing which were just sharpened rods of lead. Right or wrong, I pinned the etymology on that and didn't give it another thought.
How can we be sure that someone's knowledge of those Roman-era instruments didn't influence the etymology of "pencil lead", in spite of the story about the graphite deposit?
There are missing dots in the short explanation. I mean, between the time you discover a graphite deposit (thinking it might be lead) and the time you go to production with graphite pencils, you know very well that you're not dealing with lead. You would only persist with the naming as a deliberate inside joke. If so, who can say that the joke wasn't informed by historic knowledge of lead styluses?
Or you simply use it because then people will immediately understand what it is for?
A "stilus" (the modern spelling of the words "stylus" and "style" is a mistake, which was frequent when Latin words had been assumed to be Greek words with Modern Greek pronunciation) was a metal rod that was used to write on wax tablets. The Romans called it either "stilus" or "graphium", the latter form being directly borrowed from Greek. The Latin words "stilus" and "tabella" were used to translate the Greek words "graphion" and "deltos". The Greeks have learned to use wax tablets from the Phoenicians ("deltos" is a Semitic word) and the Romans have learned to use them from the Greeks.
The wax tablets were the main method for writing texts that could be erased later.
Besides such metal styluses that were used for writing by pressing soft materials, there existed a second kind of styluses, made of true lead metal.
This second kind, which was much less common, is based on using a soft metal and a slightly abrasive tablet surface. Drawing with such a soft metal stylus leaves a trace of metal, exactly like drawing with a graphite pencil. For instance Pliny the Elder mentions such cases of using true lead rods for drawing, e.g. for drawing fine lines on a surface to guide the writing with ink on it, like the printed lines in some modern notebooks.
Suitable soft metals are lead, silver, gold and platinum, but lead has always been many orders of magnitude cheaper than the others, so it has been frequently used for this purpose before the discovery of graphite.
Graphite is softer than any of these metals, so it leaves much more visible traces, even without using a great pressure during writing. The metal styluses leave much finer traces than graphite, so they are less suitable for writing a text with good visibility, but they allow better control for fine details in drawings.
While after graphite began to be used for pencils it immediately replaced most uses of soft metal styluses, the latter have remained popular until today for certain kinds of artistic drawings, the so-called metal-point drawings.
The most popular metal for artistic drawings is silver, because it is much cheaper than gold or platinum, while producing higher-quality drawings than lead , graphite or charcoal.
There are many such silverpoint drawings that are very beautiful.
The lead shadows of Pliny the Elder are similarly used by artists to do rough drafts before committing pen to paper. Particularly cartoonists, prior to photoshop layers.
Wait, so we didn't realise graphite and lead were different substances until after pencils were invented? Yet we never took that mix-up to the point of putting lead in pencils?
1: https://www.washingtonpost.com/lifestyle/kidspost/ever-wonde...