|
INVESTIGATIONS
|
Stone |
RI min |
RI max |
Dens min |
Dens max |
Colour |
Location |
Info |
Spectrum |
UVS |
UVL |
Reference |
|
Obsidian |
1.488 |
1.488 |
237 |
2.37 |
black
greyish |
|
53.8ct, rainbow obsidian,
cabochon |
|
inert |
inert |
ACAM Lab
2069 |
|
Obsidian |
1.489 |
1.489 |
2.36 |
2.36 |
brown |
Puno,
Peru |
Macusanite,
transparent |
|
|
|
Zeitschrift der Deutschen Gemmologischen
Gesellschaft 1995 44(1), p25-28 |
|
Obsidian |
1.489 |
1.489 |
2.35 |
2.35 |
dark
brown |
|
bright reflective
aventurescence caused by hematite and ilmenite platelets, "star
obsidian" |
|
inert |
inert |
Gems & Gemology 2003 Fall,
p233 |
|
Obsidian |
1.54 |
1.54 |
2.36 |
2.36 |
slightly
yellowish |
Atacama,
Chili |
|
|
|
|
The Journal of Gemmology 1998
Vol 26,
N°5,p321-323 |
TABLES
|
Stone |
RI min |
RI max |
Dens min |
Dens max |
Reference |
|
Obsidian |
1.48 |
1.51 |
2.3 |
2.5 |
John Sinkakas, Gemstone and
mineral data book,1972
|
|
Obsidian |
1.48 |
1.52 |
2.35 |
2.55 |
Bestimmungstabellen für Edelsteine, Birgit
Günther, 1981
|
|
Obsidian |
1.48 |
1.51 |
2.3 |
3 |
http://www.gemmology.be
|
|
Obsidian |
1.48 |
1.51 |
2.33 |
2.45 |
Tabellen zur Edelstein-Bestimmung, Pschichholz
FGA, 1975
|
|
Obsidian |
1.48 |
1.51 |
2.33 |
2.42 |
http://www.geminterest.com
|
|
Obsidian |
1.48 |
1.51 |
2.33 |
2.42 |
Gems, R Webster, 5th edition
1994
|
|
Obsidian |
1.48 |
1.51 |
2.33 |
2.42 |
Tables of Gemstone
Identification, Roger Dedeyne, Ivo Quintens, 2007
|
|
Obsidian |
1.48 |
1.51 |
2.33 |
2.5 |
Gemology Tools Professional 2010
|
|
Obsidian |
1.48 |
1.51 |
2.3 |
2.6 |
Gemmo.eu
|
|
Obsidian |
1.5 |
1.5 |
2.33 |
2.42 |
Gemme, Dati per l'identificazione, P. De Stefano
et al, 1993
|
|
Obsidian |
|
|
2.33 |
2.42 |
Joel Arem, Color Encyclopedia
of Gemstones, 1987
|
CAUSE OF COLOUR
MINERAL INCLUSIONS
|
Inclusion |
Stone |
Reference |
|
spessartine |
Obsidian |
Gems&Gemology 2005, summer
p179 |
|
sillimanite |
Obsidian |
Gems&Gemology 2005, summer
p179 |
|
indialite |
Obsidian |
Gems&Gemology 2005, summer
p179 |
LOCALITIES
|
STONE |
LOCALITIES |
REFERENCE | |||
|
rainbow
obsidian |
|
|
Jalisco |
Mexico |
Gems & Gemology 2001 Spring
p71 |
|
obsidian |
Glass Buttes (Obsidian
Buttes) |
Lake
County |
Oregon |
USA |
Gem Trails of Oregon, James R.
Mitchell 1998 |
CHEMICAL DATA (%)
|
Stone |
Colour |
Locality |
Reference |
SiO2 |
Al2O3 |
MnO |
MgO |
FeO |
TiO2 |
CaO |
Na2O |
Cr2O3 |
Fe2O3 |
K2O |
P2O5 |
Cl |
SO3 | |
|
obsidian |
|
|
Mexico |
The Journal of Gemmology 2000,
Vol 27, N°5,p282 |
75.13 |
12.46 |
|
|
|
0.08 |
0.25 |
5.24 |
0.08 |
2.01 |
4.75 |
|
|
|
|
obsidian |
slightly
yellowish |
Atacama |
Chili |
The Journal of Gemmology 1998,
Vol 26, N°5,p322 |
74.2 |
14.26 |
0.27 |
0.08 |
0.46 |
0.09 |
0.33 |
4.48 |
|
|
3.82 |
|
|
|
|
obsidian
(Macusanite) |
|
|
Peru |
The Journal of Gemmology 1998,
Vol 26, N°5,p322 |
77.98 |
0.54 |
|
|
|
13.16 |
1.34 |
|
|
|
6.98 |
|
|
|
|
obsidian
(Macusanite) |
|
|
USA |
The Journal of Gemmology 1998,
Vol 26, N°5,p322 |
74.64 |
12.48 |
0.06 |
0.44 |
0.82 |
0.12 |
2.25 |
5.66 |
|
|
2.46 |
0.24 |
0.25 |
0.58 |
|
obsidian |
|
|
USA |
The Journal of Gemmology 2000,
Vol 27, N°5,p282 |
74.61 |
12.77 |
|
|
|
0.15 |
1.12 |
4.5 |
0.08 |
1.04 |
5.74 |
|
|
|