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.
