Sapucaia pegmatite, Conselheiro Pe�a, Galileia, Minas Gerais, Brazil Link to MinDat.org Location Data.
Name Origin:
Named for Clifford Frondel (1907-2002), one of the founders of Mineralogical Society of America and one of the authors of Dana's Mineralogy, 7th edition.
Brown, Brown green, Brownish black, Green black, Dark green.
Density:
3.476
Diaphaneity:
Subtranslucent
Fracture:
Brittle - Uneven - Very brittle fracture producing uneven fragments.
Hardness:
4.5 - Between Fluorite and Apatite
Luster:
Vitreous - Dull
Streak:
brownish gray
Optical Properties of Frondelite
Gladstone-Dale:
CI meas= 0.031 (Excellent) - where the CI = (1-KPDmeas/KC) CI calc= 0.051 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2472,KPDmeas= 0.2525,KC= 0.2605 Ncalc = 1.91 - 1.92
Optical Data:
Biaxial (-), a=1.86, b=1.88, g=1.893, bire=0.0330
Calculated Properties of Frondelite
Electron Density:
Bulk Density (Electron Density)=3.38 gm/cc note: Specific Gravity of Frondelite =3.48 gm/cc.
Fermion Index:
Fermion Index = 0.0075078059 Boson Index = 0.9924921941
Photoelectric:
PEFrondelite = 13.19 barns/electron U=PEFrondelite x rElectron Density= 44.55 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Frondelite is Not Radioactive
Frondelite Classification
Dana Class:
41.09.02.02(41)Anhydrous Phosphates, etc. Containing Hydroxyl or Halogen
Chemical Formula: 
