Most commonly formed as a devitrification product of silicic volcanic glass from tuffs. Also occurs in cavities in rhyolites, andesites, and basalts.
IMA Status:
Valid Species (Pre-IMA) 1923
Locality:
Decomposed basalt at a high point on ridge running east from Hoodoo Mountain, Wyoming, USA. From an off-shore borehole, Japan (Ogihara and Iijima, 1990). Link to MinDat.org Location Data.
Name Origin:
The name reflects its inclined extinction and supposed similarity in composition to "ptilolite" (mordenite). K modifier added by zeolite nomenclatrue committee.
Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Habit:
Crystalline - Fine - Occurs as well-formed fine sized crystals.
Habit:
Tabular - Form dimensions are thin in one direction.
Hardness:
3.5-4 - Copper Penny-Fluorite
Luminescence:
Fluorescent, Short UV=light green.
Luster:
Vitreous (Glassy)
Streak:
white
Optical Properties of Clinoptilolite-K
Gladstone-Dale:
CI meas= 0 (Superior) - where the CI = (1-KPDmeas/KC) CI calc= 0.04 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2169,KPDmeas= 0.226,KC= 0.226 Ncalc = 1.47 - 1.51
Optical Data:
Biaxial (+/-), a=1.476-1.491, b=1.479-1.493, g=1.479-1.497, bire=0.0030-0.0060, 2V(Calc)=0-72, 2V(Meas)=31-48. Dispersion r > v to r < v strong.
Pleochroism (x):
none.
Pleochroism (y):
none.
Pleochroism (z):
none.
Calculated Properties of Clinoptilolite-K
Electron Density:
Bulk Density (Electron Density)=2.17 gm/cc note: Specific Gravity of Clinoptilolite-K =2.15 gm/cc.
Fermion Index:
Fermion Index = 0.01 Boson Index = 0.99
Photoelectric:
PEClinoptilolite-K = 3.22 barns/electron U=PEClinoptilolite-K x relectron= 6.99 barns/cc.
Radioactivity:
GRapi = 95.03 (Gamma Ray American Petroleum Institute Units)
Concentration of Clinoptilolite-K per GRapi unit = 1.05 (%)
Estimated Radioactivity from Clinoptilolite-K - barely detectable
Chemical Formula: 
- barely detectable