Splintery - Thin, elongated fractures produced by intersecting good cleavages or partings (e.g. hornblende).
Habit:
Blocky - Crystal shape tends to be equant (e.g. feldspars).
Habit:
Massive - Granular - Common texture observed in granite and other igneous rock.
Habit:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Hardness:
6-7 - Orthoclase-Quartz
Luminescence:
Non-fluorescent.
Luster:
Vitreous (Glassy)
Magnetism:
Nonmagnetic
Streak:
red
Optical Properties of Piemontite
Gladstone-Dale:
CI meas= -0.099 (Poor) - where the CI = (1-KPDmeas/KC) CI calc= -0.059 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2163,KPDmeas= 0.2246,KC= 0.2043 Ncalc = 1.69 - 1.72
Optical Data:
Biaxial (+), a=1.725-1.756, b=1.73-1.789, g=1.75-1.832, bire=0.0250-0.0760, 2V(Calc)=54-86, 2V(Meas)=50-86. Dispersion strong, r > v.
Pleochroism (x):
pale yellow, yellow, lemon yellow, orange, or red.
Pleochroism (y):
pale purple, amethyst violet, violet, rose, or deep red.
Calculated Properties of Piemontite
Electron Density:
Bulk Density (Electron Density)=3.48 gm/cc note: Specific Gravity of Piemontite =3.53 gm/cc.
Fermion Index:
Fermion Index = 0.0092141919 Boson Index = 0.9907858081
Photoelectric:
PEPiemontite = 6.55 barns/electron U=PEPiemontite x rElectron Density= 22.82 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Piemontite is Not Radioactive
Piemontite Classification
Dana Class:
58.02.01a.05(58)Sorosilicate Insular, Mixed, Single, and Larger Tetrahedral Groups
(58.02)with cations in [6] and higher coordination; single and double groups (n=1,2)
Chemical Formula: 
