Tyyyyie commented
The space stone that Loki uses in his scepter – tesseract.
Yashwanth3366 commented
Tesseract is the first stone to be appeared in the MCU and later it was reality stone followed by mind stone
Kush commented
Space Stone
bhagatsingh123 commented
Tesseract was seen the first in mcu
Tesseract- space stone
Appeared in Captain America: the first avenger