This can increase the probability of cultivators with Ice Spirit Root forming their Core; the Immortal Gate also has it. It's a specialty of the sea territory's depths, called Heavenly Blue Ice Jade.
Chen Mobai gave it to Yan Bingxuan a long time ago. Over the years, she has nurtured it with her spiritual power, just waiting to refine it into her body during Core Formation.
"I have prepared another gift for you. After you get the Water Element Golden Core Pill, I'll give it to you."
Chen Mobai took the Ice Marrow Pure Jade from Yan Bingxuan's hand. As he spoke, it suddenly slipped from his hand. The beautiful jade fell along the smooth ice-like skin, disappearing into a deep crevice, vanishing in an instant.
With a startled exclamation, Chen Mobai reached in, laboriously groping, and finally managed to retrieve that piece of Ice Marrow Pure Jade.
At this moment, Yan Bingxuan's snow-white cheeks were already flushed with embarrassment.