The Mercury Silver edition of the Mi 6 that was last seen when the phone was announced will soon be on sale. Unfortunately, the phone will only be sold in China. Even worse, only 100 units will be made available, which will likely disappear in seconds. The Mercury Silver edition is just the regular Mi 6 but in a super flashy chrome finished back that is almost entirely colorless and reflects like a true mirror. This extends to the back and all the sides but the front will still be black. Xiaomi did not reveal the exact launch date yet but did reveal the price, which will be RMB...
Source: http://www.gsmarena.com/mi_6_mercury_silver_edition_to_be_launched_in_china_soon-news-26403.php