Which Major Islands and Minerals of the World term is correctly associated with location or primary association: “the principal ore of zinc”, and also with “a zinc sulphide mineral”?

Correct Answer: Option A — Sphalerite. Sphalerite is correct because it is the principal ore of zinc. Sphalerite is also associated with a zinc sulphide mineral. A further identifying fact is that Sphalerite is the principal ore of zinc. Another useful fact is that Sphalerite is associated with a zinc sulphide mineral. Why the other options are incorrect: Option B — Cassiterite: It is the principal ore of tin and is associated with a tin oxide mineral with formula SnO2; those are the identifying facts of Cassiterite. Option C — Chromite: It is the principal ore of chromium and is associated with important for stainless steel and alloy production; those are the identifying facts of Chromite. Option D — Pyrolusite: It is an important ore of manganese and is associated with mainly manganese dioxide, MnO2; those are the identifying facts of Pyrolusite. Exam Takeaway: Link Sphalerite with “the principal ore of zinc” and “a zinc sulphide mineral” for quick revision.