Vegetable oil, olive oil, etc. According to relevant information, Laoshan greenstone oil can be maintained with vegetable oil, olive oil and Shanghai white oil. High-quality Laoshan bluestone can be brushed with a thin layer of oil and wiped with a soft cloth without refueling and maintenance. Laoshan Green Stone, also known as Laoshan Green Jade, is produced in Yangkou Bay at the eastern foot of Laoshan Mountain in Qingdao, Shandong Province, among which the intertidal zone in Yu Haibin is the best.