Even - Flat surfaces (not cleavage) fractured in an even pattern.
Habit:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Habit:
Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)
Habit:
Spherical - Spherical, rounded aggregates.
Hardness:
3-4 - Calcite-Fluorite
Luster:
Vitreous (Glassy)
Streak:
light brown
Optical Properties of Earlshannonite
Gladstone-Dale:
CI meas= 0.04 (Good) - where the CI = (1-KPDmeas/KC) CI calc= 0.075 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2443,KPDmeas= 0.2536,KC= 0.264 Ncalc = 1.77 - 1.79