Pyroxene Visible Spectra (generally 350 - 2500 nm)
polarizations: (a = alpha direction; b = beta direction; g = gamma
Pictures of pyroxenes showing the pleochroism
parallel to the c-axis; two crystals, one from Tanzania, the other from
parallel to the b-axis
Images of representative orthopyroxene spectra
spectrum; Enstatite (bronzite,
Fs 14.0), GRR 40, Bamble, Norway, 0.100 mm thick with Fe2+
the M2 site dominating the spectrum. Data Files: alpha; beta; gamma. Image of the alpha band on
(0.095 mm thick). Data File: alpha
spectrum; Enstatite (hypersthene,
Fs 39.5), GRR 1653, Summit Rock, Oregon, 0.10 mm thick With type Fe2+
in the M2 site dominating the spectrum and a M1 site feature near 1200
nm. Data Files: alpha;
spectrum, GRR 1087, from Tanzania, plotted as 0.500 mm
thick. This is the sample pictured above.Data Files: alpha; beta; gamma
Synthetic orthopyroxenes containing various transition elements.
spectrum, GRR 247, from Jun Ito, plotted
as 0.100 mm thick.
Data files: alpha;
- (Mg,Ni)SiO3 spectrum,
GRR 248, from Jun Ito, plotted as
0.200 mm thick. Data files: alpha;
- (Mg,Co,Mn)SiO3 spectrum,
GRR 250, from Jun Ito, plotted as 0.100 mm thick.
Data files: alpha;
Synthetic clinopyroxene containing various
Synthetic protopyroxene containing vanadium.
Images of representative clinopyroxene spectra
spectrum; Augite, GRR 13477, Maui, Hawaii, 0.100 mm thick
in the M2 site providing major features near 1000 and 2300 nm. Data
Files: alpha; beta; gamma
- Augite spectrum;
Augite, GRR 583, CIT 13748, Cedar Butte, Oregon ,
thick with Fe2+
in the M2 site dominating the spectrum. Data Files: alpha; beta;
spectrum; Diopside, GRR 472, CIT 7524, Binntal Wallis,
0.50 mm thick. This shows both
Fe2+ and Fe2+ - Fe3+
transfer. Data Files: alpha;
spectrum; Diopside, RDS 62047-70, chromian ,
Russia, 1.00 mm thick. The band at 1030 nm is from Fe2+
whereas the other features are from Cr3+. The
0.558 wt% Cr2O3.
This was taken with light
polarized along each crystallographic axis. Data Files: E||b.
spectrum; Hedenbergite, CIT-12593, from the Obersulzbach
Salzburg, Austria, 0.250 mm thick.Intervalence charge transfer between
Fe2+ - Fe3+ occurs near
790 nm and features from Fe2+ in the
M(1) site occur near 967 and 1190 nm. A feature from Fe2+
in the M(2) site occurs near 1030 nm. Data Files: alpha; beta; gamma
Special Clinopyroxene Topics:
spectrum; Jadeite from Kazakhstan,
polycrystalline mass run unpolarized and normalized to 10 mm
The spectrum is dominated by Cr3+ but also shows
band near 440 nm. Data file: Contributed data from
LAL, Moscow: unpolarized.
spectrum; Lavender jadeite from Nam Maw, Myanmar: unpolarized
Spodumene comes in various colors. Pink
ones are known as kunzite. Green, chromium-containing ones are known as
hiddenite. Then can also occur naturally green in chromium-free spodumenes due to radiation exposure. Such matrial usually fades rapidly to pink when exposed to bright light.
- Spodumene CIT-9564 spectrum, yellow green, Brazil?, 13.5 mm
- Spodumene CIT 7221 spectrum, yellow color, Minas Gerais, Brazil. 10 mm thick
- Spodumene RCH blue spectrum, blue color, Afghanistan, 10 mm thick
- Spodumene RCH yellow spectrum, yellow color, Afghanistan, 10 mm thick
- Spodumene RCH yellow-green spectrum, yellow-green color, Afghanistan, 10 mm thick
When irradiated, kunzite will turn
green. Both natural irradiation
(e.g., from the decay of naturally radioactive potassium-40) and
laboratory irradiation (e.g., X-rays and gamma rays) will serve to make
the color change occur.
Spodumene GRR 831 from Afghanistan irradiated with Cs-137 gamma rays
green color has been observed for many years, and has been
several workers including Fred Pough
Pough F, Rogers TH (1947) Experiments in x-ray irradiation of gem
stones. American Mineralogist 32, p31-43.
Spodumene, CIT 11149, green hiddenite
from North Carolina,
USA. Thickness: 2.96 mm, two polarizations on the cleavage
110 face of this Cr3+-containing spodumene.
- no other data files at this time
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