Big Creek - Rush Creek sanbornite deposit, 5 miles NE of Trimmer, Fresno Co., California. Link to MinDat.org Location Data.
Name Origin:
Named for John Muir (1838-1914), American geologist and explorer who made early observations in geology in the Sierra Nevada Mountains, California, USA.
Anhedral Grains - Granular minerals without the expression of crystal shapes
Hardness:
2.5 - Finger Nail
Luster:
Vitreous (Glassy)
Streak:
light orange
Optical Properties of Muirite
Dichroism (e):
orange.
Dichroism (w):
colorless.
Gladstone-Dale:
CI meas= -0.054 (Good) - where the CI = (1-KPDmeas/KC) CI calc= -0.071 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1843,KPDmeas= 0.1815,KC= 0.1722 Ncalc = 1.65 - 1.66
Optical Data:
Uniaxial (+), w=1.697, e=1.704, bire=0.0070.
Calculated Properties of Muirite
Electron Density:
Bulk Density (Electron Density)=3.46 gm/cc note: Specific Gravity of Muirite =3.86 gm/cc.
Fermion Index:
Fermion Index = 0.1 Boson Index = 0.9
Photoelectric:
PEMuirite = 244.96 barns/electron U=PEMuirite x rElectron Density= 848.20 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Muirite is Not Radioactive
Chemical Formula: 
