Quality evaluation is paramount for black truffles (Tuber melanosporum or Tuber indicum). Buyers should prioritize aroma intensity, which should be earthy and pungent, not musty. The peridium (skin) must be firm to the touch; softness indicates decay. Internally, the gleba (flesh) should display a dark brown to black color with fine, white, well-defined marbling. For wholesale, truffles are graded by size: Extra Class (uniform shape, >20g), First Class (slight defects, >15g), and Pieces (broken or small specimens). Always request high-resolution cross-section photos or videos from the supplier before shipment.