check #s 2, 3 & 4 in sunlight vs. dim indoor lighting...Greenland has tenebrescent rocks such as hackmanite & tugtupite, those look like possibilities although unlikely. if you have a long wave and/or short wave UV light, see if any of them fluoresce
EDIT: the white ones are also possibly cryolite. Can you check the hardness? See if a steel knife will leave a scratch/gouge in the rock, then try copper (not a penny bc they aren't really copper anymore )