Can anyone recommend Chinese names that mean "a rainfall of jade"?
if the family name is 白, may i suggest, for rainfall:

霝(u+971d), which means "light rain, drops of rain". it has a heritage since oracle bone script, used for people's name at that period.

http://dict.revised.moe.edu.tw/cgi-bin/cbdic/gsweb.cgi?o=dcbdic&amp;searchid=W00000003720

another one is: 澍(u+6f8d), which means "timely rain; to rain, to moisten"

http://dict.revised.moe.edu.tw/cgi-bin/cbdic/gsweb.cgi?o=dcbdic&amp;searchid=W00000009123

for jade, roughly all characters belong to the 96 radical "玉" is jade related. i would suggest these four:

璐(u+7490), 瑾(u+747e), 琨(u+7428), or 琦(u+7426)

so some combinations of a boy's name:

霝璐, 霝瑾, 霝琨, 霝琦, or 澍璐, 澍瑾, 澍琨, 澍琦.

before making any decision, would you consider the baby's 生辰八字? in the past, it's one of the most important factor in choosing any name.

have fun :)