Opal Empire Gems Co.
明泰寶石公司 (Opal Empire Gems Co.) - Member of HKGMA
明泰寶石公司 (Opal Empire Gems Co.) - Member of HKGMA
Opals Mine Factory Ltd. - Member of HKGMA
鄭明興閃山雲珠寶廠有限公司 (Opal House Ltd.) - Member of HKGMA
中華琥珀國際有限公司 Palminic International Co. Ltd. - Member of HKGMA