As a replacement of NaMn amphibole nemansilite and serandite and as the main or sole constituent of tiny veinlets.
IMA Status:
Approved IMA 1996 (Dana # Added)
Locality:
The Woods mine 30 km NNE of Tamworth, New South Wales, Australia. Link to MinDat.org Location Data.
Name Origin:
For William Noel Benson (1855-1957), of the University of Otago, in recognition of his pioneering research in the Great Serpentine Belt and New England Fold Belt of New South Wales, Australia.
Brittle - Uneven - Very brittle fracture producing uneven fragments.
Habit:
Blocky - Crystal shape tends to be equant (e.g. feldspars).
Habit:
Cryptocrystalline - Occurs as crystals too small to distinguish with the naked eye.
Habit:
Crystalline - Fine - Occurs as well-formed fine sized crystals.
Hardness:
4 - Fluorite
Luster:
Vitreous - Greasy
Streak:
yellow brown
Optical Properties of Noelbensonite
Gladstone-Dale:
CI meas= 0.03 (Excellent) - where the CI = (1-KPDmeas/KC) CI calc= 0.05 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2122,KPDmeas= 0.2166,KC= 0.2233 Ncalc = 1.86 - 1.88
Optical Data:
Biaxial (-), a=1.82, b=1.845, g=1.85, bire=0.0300, 2V(Calc)=46, 2V(Meas)=46. Dispersion distinct to strong, r > v.
Calculated Properties of Noelbensonite
Electron Density:
Bulk Density (Electron Density)=3.61 gm/cc note: Specific Gravity of Noelbensonite =3.87 gm/cc.
Fermion Index:
Fermion Index = 0.05 Boson Index = 0.95
Photoelectric:
PENoelbensonite = 133.00 barns/electron U=PENoelbensonite x rElectron Density= 480.13 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Noelbensonite is Not Radioactive
Noelbensonite Classification
Dana Class:
56.02.03.04(56)Sorosilicate Si2O7 Groups and O, OH, F. and H2O
(56.02)with cations in [4] and/or >[4] coordination
Chemical Formula: 
