Literature Reference: 瑜：美玉也。——《说文》；桦：白桦，木也。——《玉篇》 Yu: A fine jade, from 'Shuowen'; Hua: Birch, a tree, from 'Yupian'.
瑜:
The radiance of jade, auspiciousness and well-being, grace and composure.
桦: The tree species, birch. "Birch" symbolizes the toughness akin to a tree, unyielding to wind and rain, metaphorically representing a robust physique conducive to good health.
Meaning: Yu symbolizes precious jade, representing beauty and value; Hua symbolizes the birch tree, embodying resilience and vitality.