Antique Chinese Carved Jade Cicada. Han Dynasty. (2nd - 1st Century). Light Celadon With Calcification. Approximately 2 3/4" Long x 1 1/4" Wide.
For A Similar Example:
Chinese Jade Through The Centuries - The China Institute In America October 24, 1968 - January 26, 1969 Item 31. Dated As Han.