Analogy (mineral → gemstone): Complete the pair. Given: Carbon → Diamond (diamond is a crystalline form/gem derived from carbon). Asked: Corundum → ? Choose the correct option.

Given data

• Carbon → Diamond (a gemstone form of carbon).
• Corundum (Al₂O₃) has gem varieties: ruby (red) and sapphire (other colours).

Concept/Approach Match "mineral → celebrated gemstone variety".

Reasoning The classic analogy pairs corundum with its famed red gem variety: Ruby.

Note Sapphire is also corundum, but ruby is the most conventional single answer in such analogies.