3. Diffusion
Star Sapphires-
Use of chemicals/heating on the
surface of the stone to
change the color or add a
star to a stone that normally doesn't contain
one
4. Linde
Stars(Artificial/Lab Created Star
Sapphires)-
Stone is synthetic, star and
color
synthetic as
well
5. Fracture
Filled-
Oil, Glass, Resin or Epoxy fills cracks
or fractures, usually
unable to detect without
optical instrumentation
At Simply
Sapphires, the great majority of our stones are
natural untreated star
sapphires (and star
rubies), and thats what we look
for.
How
Can
You As
a consumer tell
the difference? You
really
can't, It
really
takes a
well
equipped
laboratory, to detect the
intricate
processes
performed. My
experience has been jewelers and
even most
gemologists
don't have the proper
equiptment to
give you
anything more
than an
educated
guess. so if you have
any
question, send it to the AGTA, GIA or EGL gem
lab,
or a well
recognized
established
lab.
Tips on What
to Look For On A Star Sapphire or Star
Ruby
1. First thing to
look at is the bottom, if there is an "L" stamped
in the stone, it's a Linde
Star and synthetic...
Linde stars were manufactured en masse
by the
Linde
division
of Union
Carbide since about the
early
1950’s.
2.
Next look for
imperfections within the stone, or an unevenness
on the bottom, or stripes or
bands of color that
shows through the top, most naturals
have one or
more of
these natural imperfections.
3.
Take a good look
at
the star itself,
using a flashlight, most
natural
stars do not have a
"perfect" star, whereas the
natural will likely have one or more of the six
legs uneven in
length, or
maybe
not
perfectly
straight...
the star must travel around following
the light
source,
if
the star is
stationary it is definitely
synthetic.
The most
common
synthetics jump out as
way are too perfect looking and the star might
only
move one
direction if at all.
4. Color is
extremely
important,
richer the
color the
better
the
stone,
pretty
simple.
5. The legs of the
star should be
complete and sharp, with no missing
or broken legs, and each ray should extend
to the
girdle of the
stone.
6. The more transparent or translucent
the
stone the better.
Tricky though, because
sometimes
with too
much transparency
the star may not be as
evident.
How rare are these gems? For every 100
faceted corundum
(ruby
and sapphire) mined,
approximately three stars are
discovered. One will
have good color and a bad
star. One will have a
great star and bad color.
Only
one out of a
hundred will have a good star and good
color.
Fine stars are pretty rare. Until the
1960s, these stones
always sold for more than the
faceted ruby. For example, in the late 19th
century, three carat star rubies went
for $3000
per
carat.
