|
Gemstones |
RI |
Optic character |
Disp. |
UV |
SG |
Hardness |
Characteristics/with
loupe |
Characteristics/under
a microscope |
Spectra |
Additional
information and tests |
|
Diamond
|
2,417
|
SR
|
high
.044
|
if
there is UV fluorescence it is mostly blue
LW-SW
LW
is always stronger
|
3.52
|
10
|
adamantine
luster
|
fine
breaks in the girdle area,
cleavage,
natural, extra facets, naturals with trigons, steplike fracture, polish
marks in different directions, angular crystal inclusions,sharp facet
edges
|
Cape spectrum
violet
area 415.5nm band
|
high relief in methylene iodide liquid,
hardness
pencil,
termal
conductivity probe
|
|
Synthetic
rutil
|
2,616
-2.903
|
DR
|
very
high
.330
|
no
reaction
|
4.26
|
6-61/2
|
bright
vitreous luster,
rounded
facet edges,
doubled facet edges,
strong dispersion
|
strong
doubling,
polish
marks in same directions,
air
bubbles
|
cut at 430nm
|
yellowish
colour,
high
relief in methylene iodide liquid,
high dispersion,
hardness
pencil,
termal
conductivity probe
|
|
Strontium
Titanate
|
2,409
|
SR
|
very
high
.190
|
no
reaction
|
5.13
|
5-6
|
bright
vitreous luster,
rounded
facet edges,
strong dispersion |
polish
marks
polish
marks in same directions,
air
bubbles
|
none
|
high
relief in methylene iodide liquid,
high
dispersion,
hardness
pencil,
termal
conductivity probe
|
|
Cubic
Zirconia |
2,15
|
SR
|
high
.060
|
either
no reaction or yellow-orange
SW |
5.95
|
8
1/4-
8
1/2
|
bright
vitreous luster,
strong
dispersion
weak
see
through
|
tiny
air bubbles called stringers, whitish flux like inclusions
|
none
|
high
relief in methylene iodide liquid,
diamond
pen
termal
tester |
|
GGG
|
1.970
|
SR
|
high
.045
|
either
no reaction or
medium
orange LW, from medium to strong pinkish orange LW
|
7.05
|
6
1/2
|
bright
vitreous luster,
see
through
rounded
facet edges
|
polish
marks, triangle or hexagonal metalic inclusions, air bubbles,polish
marks in same directions
|
none
|
medium
relief in methylene iodide liquid,
brownish
colour,
hardness
pencil,
termal
conductivity probe
|
|
Zircon
|
1.925-
1,984 |
DR
|
medium
to high
.038
|
either
no reaction or
weak
yellowish LW-SW
|
4.70
|
7
1/2
|
subadamantine
luster
worn
out facet edges
see
through |
strong
doubling, triangular inclusions,
polish
marks in same directions |
653.5
nm
diagnostic
|
medium
relief in methylene iodide liquid,
hardness
pencil,
termal
conductivity probe
|
|
YAG
|
1,833
|
SR
|
medium
.028
|
either
no reaction or
medium
orange LW-SW
|
4.55
|
8
1/4
|
bright
vitreous luster,
see
through
weak
dispersion
|
polish
marks in same directions, air bubbles or tubular inclusions
|
none
|
in
methylene iodide liquid the stone almost dissapears,
diamond pen
termal
tester |
|
Synthetic
sapphire
|
1.762-
1.770
|
DR
|
low
.018
|
either
no reaction or
weak
bluish white SW
|
4.00
|
9
|
strong
see through
weak
dispersion |
polish
marks in same directions, air bubbles,
weak
doubling |
none
|
in
methylene iodide liquid the stone almost dissapears,
hardness
pencil,
termal
conductivity probe
|
|
Synthetic
Spinel
|
1.730
|
SR
|
low
.0.20
|
from
strong to very strong chalky white or yellowish SW
|
3.64
|
8
|
vitreous
to bright
strong
see through
weak
dispersion
|
polish
marks in same directions, air bubbles or tubular inclusions |
none
|
in
methylene iodide liquid the stone almost dissapears,
hardness
pencil,
termal
conductivity probe
|
|
Glass
|
1.48to
1.70
|
SR
|
low
to high
mostly
.037
|
variable,
if any stronger in SW
|
ekseri
2.30dan
4.50e
|
5-61/2
|
vitreous
to dull
molded
facets,
see through;much
rounded
facet edges,
poor
luster |
air
bubbles, swirl
marks,
polish
marks
concoidal
fracture,
orange
peel surface condition,
polish
marks in same directions |
none
|
dissapears
in methylene iodide liquid,
hardness
pencil,
termal
conductivity probe
|
|
Doublets
|
Different
RI on crown and pavillon
|
|
|
variable
|
|
|
crown
and pavillon have different luster, line on the girdle, looking table
down on a white surface
red
ring effect (garnet and glass doublets)
concoidal
fracture.
|
different
in crown and pavillon
|
different
in crown and pavillon if there is any
|
crown
and pavillion looks different in methylene iodide liquid, most of the time only
separation plane shows,
hardness
pencil,
termal
conductivity probe
|
|
Synthetic
Moissanite |
2.648
-2.691 |
DR |
very
high
|
|
3.22 |
9.5 |
metalic,
bright vitreous luster |
doubling,
typical needle inclusions, |
|
moissanite
tester
click
on
Synthetic
Moissanite
|
