Step 1: Understanding the question.
The question asks about a mineral that exhibits luminescence when exposed to ultraviolet (UV) light. Scheelite is well known for its ability to fluoresce when subjected to UV light, producing a bright blue glow.
Step 2: Analyzing the options.
(A) Cassiterite: Cassiterite is not known for fluorescence under UV light.
(B) Wolframite: Wolframite does not exhibit luminescence under UV light.
(C) Tantalite: Tantalite is not a known fluorescent mineral under UV light.
(D) Scheelite: Correct — Scheelite is known for its fluorescence under UV light, making it the correct choice.
Step 3: Conclusion.
The correct answer is (D) Scheelite, as it is the mineral that exhibits luminescence when exposed to UV light.