- Duong quoc thang Ltd
- mineral ore,crystal sand.
- Address:duong 26
- Hai Hoang Gia Gems Co., Ltd.
- Gemstone,antique,jewelry,Crystal mineral,melo,sapphire,ruby,spinel,aquamezin,Gemstones,Mineral,Crystal, mnerals,Minerals,Jewellery,Jewelry.
- Address:70 Ngo Thi Nham St. , Hai Ba Trung Dist.
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