正长石 (正長石) zhèngzhǎngshí
          
              zhèngzhǎngshí 
              
              noun 
              orthoclase 
              Domain: Modern Chinese 现代汉语
              
                , Subdomain: Geology 
              
              
              
              
                Notes: Chemical formula: KAlSi3O8; a rock-forming mineral, type of feldspar (CC-CEDICT '正長石')