Aggregates - Made of numerous individual crystals or clusters.
Hardness:
1 - Talc
Luster:
Earthy (Dull)
Streak:
white
Optical Properties of Swinefordite
Gladstone-Dale:
CI meas= 0.066 (Fair) - where the CI = (1-KPDmeas/KC) CI calc= -0.098 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2369,KPDmeas= 0.2016,KC= 0.2158 Ncalc = 1.47 - 1.6