Antique Chinese carved rock crystal pin, mount marked sterling. Measurements in pics, no significant issues. Does seem to have a pink tint, so possibly light pink rose quartz.

As per Margaret Duda's research, these donkey amulets should be hung upside down with hooves in the air to represent the white donkey of Zhang Guolao, one of the Eight Daoist Immortals. A symbol of endurance and perseverance. this mythic beast could carry Zhang Guolao one thousand miles without resting.