Chondrite meteorites. Polymorph of forsterite and replaces ferroan forsterite grains.
IMA Status:
Approved IMA 1969
Locality:
Tenham, Austalia, chondrite. Link to MinDat.org Location Data.
Name Origin:
Named for Alfred Edward Ringwood (1930-1993), geochemist and petrologist, Research School of
Earth Sciences at the Australian National University in Canberra, Australia.
Blue gray, Colorless, Light violet, Purple, Smoky gray.
Density:
3.9
Habit:
Anhedral Grains - Granular minerals without the expression of crystal shapes
Habit:
Microscopic Crystals - Crystals visible only with microscopes.
Optical Properties of Ringwoodite
Gladstone-Dale:
CI meas= 0.032 (Excellent) - where the CI = (1-KPDmeas/KC) CI calc= -0.079 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2194,KPDmeas= 0.1969,KC= 0.2034 Ncalc = 1.71 - 1.79
Optical Data:
Isotropic, n=1.768.
Calculated Properties of Ringwoodite
Electron Density:
Bulk Density (Electron Density)=3.88 gm/cc note: Specific Gravity of Ringwoodite =3.90 gm/cc.
Fermion Index:
Fermion Index = 0.04 Boson Index = 0.96
Photoelectric:
PERingwoodite = 1.53 barns/electron U=PERingwoodite x rElectron Density= 5.94 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Ringwoodite is Not Radioactive
Ringwoodite Classification
Dana Class:
51.03.03.01(51)Nesosilicate Insular SiO4 Groups Only
(51.03)with all cations in octahedral [6] coordination
Chemical Formula: 
