- Kum Kang Quartz Co., Ltd.
- Address:422 Chong-ri,Yeongcheon-ri ,Dongtan-myeon ,Hwaseong-si
- Worldex
- Address:360,Hanggok-ri,Goa-eup ,Gumi-si
- SAC
- Address:175-87 ANKUK BLDG. ANKUK-DONG, JONGRO-GU
- Seoul Quartz Co., Ltd.
- Address:345,Gasan-dong ,Geumcheon-gu
- JBSC Asia
- Address:482-5, Yeonsan-Dong,
- SLPC Global Co. LTD.
- Address:2005 Hanbit Plaza Shinchon Dong
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