The Black Diamond Apple, grown in Tibet's Nyingchi region, Its distinct purple color is a result of the high altitude (over 3,500 m) where the temperature fluctuates wildly between night and day with the apples exposed to intense ultraviolet light https://t.co/xE6Dtb2tsH https://video.twimg.com/ext_tw_video/1789175235100426241/pu/vid/avc1/720x720/1k8qkMKMrP1PAvQy.mp4?tag=12