Which Major Islands and Minerals of the World term is correctly associated with important identifying fact: “a lead sulphide mineral with formula PbS”, and also with “the principal ore of lead”?

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