珀

Left side is the jade radical - the side-form of 玉 with its dot dropped. As a radical, this shape always means jade, never king. Marks 珀 as a precious stone. Same jade-family: 玛 agate, 珍 precious, 珠 pearl, 玻 glass, 琥 jade carving (琥珀 amber).

Right side 白 supplies the sound - bái → pò, drifting through the Old Chinese b/p alternation that links many 白-phonetic characters. Faint semantic hint: amber's translucent honey-gold can shade toward pale or milky. Most often seen in 琥珀 (amber). Same phonetic in 拍 clap, 怕 fear, 伯 uncle, 泊 moor, 帕 handkerchief.