Māma bǎ nǎinai liú xià de jièzhǐ shōu hǎo, rúhuòzhìbǎo.
Mom carefully put away the ring Grandma had left her, treasuring it like a precious gem.
Tips
history
From the Song-dynasty letter 《与胡邦衡书》 by Li Guang (李光): 忽蜀僧行密至,袖出寂照庵三字,如获至宝 — 'Suddenly the Sichuan monk Xingmi arrived, drew three characters from his sleeve, and I treasured them as if they were jewels.'
grammar
Pattern: subject + 如获至宝, or as a comparison after 一样/似的. Often paired with verbs of obtaining (得到, 找到, 收到) or treasuring (珍藏, 收好).