璞 (pú) refers to jade still encased in raw stone — it must be cut and polished to reveal its beauty. The word is heavily used as a metaphor for unrecognized talent. Compare with the chengyu
璞玉浑金 (an unspoiled gem and unrefined gold) and the legend of
和氏璧 (He Shi's Jade) about a craftsman whose unrecognized
璞玉 was twice mistaken for ordinary stone.