⛲ Fountain 🖊 Pen emoji is a picture of a quite old-fashioned item used for writing, which works on ink, injected inside of it from time to time (it is not much different from the one represented by ✒️ Black Nib emoji). This emoji is unsurprisingly used in the meanings related to writing. It may be a symbol of signing some documents or writing letters or anything of that sort.
Examples of using
“I collect old-fashioned pens 🖋️”
“Calligraphy is a real art 🖋️”