Thank you for submitting your item for appraisal. This appears to be a chinese late 20th century stone carving, made from Aventurine quartz and possibly prehnite. The stone has been chemically treated and the oils used have turned brown on the surface. The Guanyin is depicted in a sitting position holding her hand in a blessing gesture, holding a medicine jar with the other, an aureole behind the head. It is a very decorative modern stone carving. The estimate is based on similar stone carvings offered or sold at auction.