Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Habit:
Foliated - Two dimensional platy forms.
Habit:
Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)
Hardness:
1.5-2 - Talc-Gypsum
Luster:
Pearly
Streak:
white
Optical Properties of Minnesotaite
Gladstone-Dale:
CI meas= 0.028 (Excellent) - where the CI = (1-KPDmeas/KC) CI calc= 0.028 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1993,KPDmeas= 0.1993,KC= 0.205 Ncalc = 1.62