Cassiterite

Was competing in a challenge walk this weekend, and a set of general knowledge questions included naming the main ore of tin (I had no idea!). A quick Google (shhh! Anyway, we didn't win) revealed the answer as cassiterite. In various table quizzes I seem to remember these "what's the main ore of X" as common enough, but I still never have the correct answer. My question is, does anybody? Who is expert in metal ores? Are they social enough to communicate with others in a table quiz or online? Who makes this interesting?

Acanthite - Silver
Chromite - Chromium
Hematite - Iron (obvs!)
Ilmenite - Titanium
Magnetite - Iron
Cinnabar - Mercury (HgS)
Pentlandite - Nickel
Sphalerite - Zinc
etc.