Green gray, Green black, Grayish black, Dark green, Dark gray.
Density:
3.52 - 3.57, Average = 3.54
Diaphaneity:
Transparent to translucent
Fracture:
Brittle - Generally displayed by glasses and most non-metallic minerals.
Habit:
Foliated - Two dimensional platy forms.
Habit:
Massive - Uniformly indistinguishable crystals forming large masses.
Hardness:
6.5 - Pyrite
Luminescence:
Non-fluorescent.
Luster:
Pearly
Streak:
colorless green gray
Optical Properties of Chloritoid
Gladstone-Dale:
CI meas= 0.038 (Excellent) - where the CI = (1-KPDmeas/KC) CI calc= 0.018 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2094,KPDmeas= 0.2049,KC= 0.2131 Ncalc = 1.74 - 1.76
Optical Data:
Biaxial (+), a=1.713-1.73, b=1.719-1.734, g=1.723-1.74, bire=0.0100, 2V(Calc)=78-80, 2V(Meas)=36-89. Dispersion r > v.
Pleochroism (x):
greenish gray, olive green, colorless, or greenish blue.
Pleochroism (y):
bluish gray, indigo, or bluish green.
Calculated Properties of Chloritoid
Electron Density:
Bulk Density (Electron Density)=3.43 gm/cc note: Specific Gravity of Chloritoid =3.47 gm/cc.
Fermion Index:
Fermion Index = 0.01 Boson Index = 0.99
Photoelectric:
PEChloritoid = 5.82 barns/electron U=PEChloritoid x rElectron Density= 19.95 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Chloritoid is Not Radioactive
Chloritoid Classification
Dana Class:
52.03.03.01(52)Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O
Chemical Formula: 