What mineralogical feature differentiates a diamond from granite?

• A. Crystalline structure
• B. Color differences
• C. Size differences
• D. Age differences

Answer: (A)

Crystalline structure is the distinguishing feature. Diamond is a single mineral with a highly ordered crystal lattice where each carbon atom bonds to four others in a three‑dimensional tetrahedral network. This uniform, well-defined arrangement gives diamond its exceptional hardness and a specific, regular internal structure. Granite, in contrast, is a rock composed of several different minerals (like quartz, feldspar, and mica), each with its own crystal structure. The overall appearance and properties of granite come from this mix, not from one uniform atomic arrangement. Color, size, and age can vary within both diamonds and granite and aren’t reliable ways to tell them apart.