I use Google images too, it can be helpful sometimes ;] In this case, though, I looked up "pluma" to see what I got and I only get fountain pens and quills. The only three results I get that are not those are something similar to a marker and two ballpoint pens; then again, the web is Dreamstime, which is not Spanish nor from any Spanish speaker country (it is from the USA and its CEOs are Romanian, I think).
I looked it up on the Spanish official dictionary and got nothing either, only a synonym for "bolígrafo", but it is called, apparently "pluma atómica" (?) in Mexico... if some Mexican (or other Spanish speakers!) could tell us if they shorten that to "pluma" (as a translation for "ballpoint pen", then), it would be great :]
I disagree. I asked a coworker from Mexico for un boligrafo, and he wasn't sure what I was talking about at first. When I pointed at his pen, he corrected me with "una pluma", and explained that although boligrafo is also correct, it's incredibly rare in the common lexicon there.
Pluma vs. boligrafo. In high school, learning Castilian Spanish, we were taught 'pluma'. In college, learning Latin American Spanish, it was 'boligrafo'. A friend I used to work with, whose family was from Mexico told me pluma is like an old-fashioned quill pen or fountain pen. A boligrafo is an everyday ball-point pen. I suspect it changes with location and age of speaker.
It's the same in English -- "pen" originally referred to using a feather to write with, but it's still commonly used for ink pens. Before ball-point pens there were fountain pens, too, but people still just say "pen" instead of specifying "ball-point pen."
"writing implement," late 13c., from Old French pene "quill pen; feather" (12c.) and directly from Latin penna "a feather, plume," in plural "a wing," in Late Latin, "a pen for writing," from Old Latin petna, pesna, from PIE pet-na-, suffixed form of root pet- "to rush; to fly" (see petition (n.)).
Latin penna and pinna "a feather, plume;" in plural "a wing;" also "a pinnacle; battlement" (see pin (n.)) are treated as identical in Watkins, etc., but regarded as separate (but confused) Latin words by Tucker and others, who derive pinna from PIE *spei- "sharp point" (see spike (n.1)) and see the "feather/wing" sense as secondary.
In later French, this word means only "long feather of a bird," while the equivalent of English plume is used for "writing implement," the senses of the two words thus are reversed from the situation in English. Pen-and-ink (adj.) is attested from 1670s. Pen name is recorded from mid-19c." -- Online Etymology Dictionary, http://www.etymonline.com/index.php?term=pen