Are China, Hongkong Gold and China Gold the same company?

Not the same company.

Hong Kong Zhongjin, a Hong Kong company, is a trademark of a legal person enterprise introduced to the mainland in recent years.

China Gold is a domestic company.

Both companies have registered their trademarks in China, but they are not gold enterprises designated by the state.

It's good in both companies. At present, gold from Hongkong and China sells quite well in China.