A red corundum (sapphire) IS ruby. Theer is no such thing as a red
sapphire.
Jerry in Kodiak
Has anyone mentioned Y.A.G. ? that stuff is very bright RI about 1.8
or so as opposed to diamond approx 2.4 RIor Zircon ? Some of the
blues look like the irradiated diamond shades and sparkle quite
nicely approx 1.9 RI - goo
Theer is no such thing as a red sapphire.
Oh yes there is.
Corundum which gets its red color from chromium is ruby. There are
corundums that get their red color from other material and don’t show
the absorption lines and they must be referred to as “red Sapphire”
or “red corundum”.
I can see that you don’t look up facts about Corundum. I already
told you that Rubies and Sapphires are brothers and sisters. A
Sapphire has more colors then a rainbow, and red is but a small
fraction of the colors possessed by a Sapphire. Also check your
spelling, There is not spelled theer. The next thing you’ll want to
tell me is that there is no such thing as a purple Sapphire. The art
of learning is to admit when we make mistakes. Go ahead now and admit
your wrong.
Mark Gerrasch
The art of learning is to admit when we make mistakes. Go ahead now and admit your wrong.
Hey Mark, be careful way up there on that horse… Pretty high up…
Jerry has, if my memory serves (and it doesn’t always) been here
on Orchid almost as long as I have, and I’ve been here just about
since Hanuman started the thing over 15 years ago or so. You’re about
the first one I can recall who’s ever suggested he’s in need of
learning. Everyone makes an occasional minor mistake. Get over it.
Oh, and as to typos? Just wait till your fingers get a bit older too.
I make lots of them, even with a spell checker. Invisible until
after I hit “send”, then they stick out like sore thumbs. (The last
week, while traveling, was even worse, typing on an iPad…) They
happen. Get over it. Oh, and while I’m at it, I’ll look in the mirror
too. I’ve had to get bumped off a high horse now and then too,
especially when something rubs me the wrong way and I don’t think
before replying. Relax. It’s a new year. With luck, perhaps it will
be less “interesting” than the last one…
Peter
Corundum which gets its red color from chromium is ruby. There are corundums that get their red color from other material and don't show the absorption lines and they must be referred to as "red Sapphire" or "red corundum".
This is somewhat correct, but deeper look into science of corundum
color is required at this point.
Corundum is nothing but oxide of aluminum Al(2)O(3). As far as
it is probably the simplest composition except diamond. If
trivalent chromium is present, than corundum acquired red color and
called Ruby. To become blue - presence of iron is required, and not
just any iron but mixture of trivalent and bivalent iron in equal
amounts. The greater the amount of mixture as a whole, the more color
saturation. If vanadium is present, the color becomes bluish-green. If
there is only half of bivalent iron as trivalent one - the color
becomes green. To make yellow we need trivalent iron and oxygen;
pink-orange (padparadschah) - trivalent chromium and oxygen. All these
chromophores can be present in combinations in single crystal given
rise to many different colors in various saturation levels. So
corundum can be virtually any color.
Corundum of bright red to to violet red is called Noble Ruby (old
designation is oriental Ruby). Pure bright red also known as “pigeon
blood ruby”. If iron is present together with chromium, the color
become brownish-red and depending on a shade names like sangena ruby,
vermeil ruby, and etc. are used. Once color approaches brownish-pink,
it is no =longer ruby, but a pink sapphire. Any corundum will show
absorption lines in spectral analysis, but wave length will be
different, depending on composiiton.
Leonid Surpin
Oh yes there is.
Corundum which gets its red color from chromium is ruby. There are corundums that get their red color from other material and don't show the absorption lines and they must be referred to as "red Sapphire" or "red corundum".
I talked to a Gemologist/appraiser that has impeccable credentials,
he said that regardless of what causes coloration of the corundum, if
it is red, it is ruby. Unless you can cite from a reputable
Gemological source, preferably G.I.A., I assume it is anecdotal and
false info.
Richard Hart G.G.
Denver, Co.
This is very interesting. When it comes to
objective/physical/factual tests, how does corundum differ from
sapphire?
I am also interested in biological miners and read somewhere that
there are “gold bugs” (microbes which use Au in metabolism). Might
there also be corundum bugs?
Tony, You wrote:
There are corundums that get their red color from other material and don't show the absorption lines and they must be referred to as "red Sapphire" or "red corundum".
Are you referring to the beryllium diffused material? As far as I
know there is no other chromophore besides chromium oxide which
produces a true red in corundum in nature. As for the diffused
material I consider that to be on a par with simulants.
Jerry in Kodiak
Mark, You wrote:
Sapphire has more colors then a rainbow, and red is but a small fraction of the colors possessed by a Sapphire.
May I suggest that you might better have said :
“red is but a small fraction of the colors possessed by corundum”,
rather than sapphire? I repeat, when corundum is red it is defined to
be ruby. Hues other than red in corundum are "… sapphire. For
example “pink, yellow, orangy red, etc. In the case of pinkish orange
it may be called padparascha. If it is red however it is ruby by
definition. If you have a corundum which is only “kinda red”, as in
brownish, orangy red, then it may be brownish, orangy corundum, but
not red sapphire. Now, in the case of the beryllium diffused corundum
which has been flooding the market in Chantaburi the past several
years, well that’s a whole different discussion. Frankly I don’t know
just what to call that. You also wrote: ’ tell me is that there is no
such thing as a purple Sapphire.” I wouldn’t think of trying to tell
you there is no such thing as purple sapphire, Mark. As a matter of
fact I have several fine specimins of that variety. Color change too.
Also green and yellow as well for that matter.
Jerry in Kodiak
When it comes to objective/physical/factual tests, how does corundum differ from sapphire?
Corundum is geological term. There are no gemstone named corundum.
When corundum achieve notable color and transparency, than it
becomes of interest to gemologists and gets names like Ruby, or
Sapphire.
Leonid Surpin
Unless you can cite from a reputable Gemological source, preferably G.I.A., I assume it is anecdotal and false info.
In GIA parlance, Ruby is red corundum of saturation 3 and higher.
Below 3 - it is pink sapphire.
Leonid Surpin
Maybe I should start signing myself Tony Konrath F.G.A. (Fellow of
the Gemmological Association - the UK equivalent of the G.I A.)
Unless the color comes from chromium it’s not designated as ruby.
When it comes to objective/physical/factual tests, how does corundum differ from sapphire?
Sapphire and ruby are both varieties of corundum. Corundum in it’s
pure form is aluminum oxide. Introduce a little bit of other elements
and you produce ruby or sapphire, depending on the element.
Basically, introduction of iron produceses red, titanium gives it the
blue. Other colors result from the presence of other elements and
varience in the ratios thereof. For those of you who are sticklers
for detail, I know it’s not quite that simple but I hope it suffices
for a quick and dirty reply.
Jerry in Kodiak
Mark,
If you put a White Sapphire next to any number of diamond substitutes, you'll see that the sapphire looks dead as far as reflecting light
If you are talking about commercially cut colorless sapphire, I
agree. But custom cut, and I mean where the facets meet and the
polish is superb (generally accomplished on ceramic), then I strongly
disagree. I have cut dozens of diamond substitutes in colorless
synthetic sapphire and they compare very well when the stone is cut
to the precisely correct angles. I can assure you, they are not
“dead”.
And I have almost a dozen dealers on my customer list for these.
Wayne Emery
thelittlecameras.com
I am new to following the Orchid threads. On the one hand the
is very useful and I am very thankful for it. On the
other hand I sometimes find it unpleasant and even a little
distressing to read these. I do not feel like it is necessary for
members to be so aggressive while debating facts with each other. I
would like to request that we keep comments to facts and not
insults. Lets all treat each other with respect. Also, please use
spell check Thank you everyone for sharing your knowledge.
May I suggest that you might better have said : "red is but a small fraction of the colors possessed by corundum", rather than sapphire?
The colour variations described in this thread make me wonder
whether a rare “Jem” in the jewelry business like the guy in the
BBC-diamond video might come up with a lab-made sapphire to surpass
the durability-rarity-aesthetics score of nature-made sapphire.
Merely turning a diamond red seems to mean it fetches premium price.
Conversely the natural yellow-brown colour of Argyle diamonds from Oz
seems to have arbitrarily lowered their price.
When we discussed alternate colours of gold, a participant said that
colloidal gold in glass gave the glass a very pretty red colour (one
might also wonder why Swarovsky hasn’t produced gold glass crystal).
What happens to the colour of lab-made corundum when various precious
metals are added to it? If the colour is strikingly aesthetic and the
formula is as closely guarded as the formula for Newcastle brown ale
then we could have a case of the synthetic getting a higher overall
score than the natural stone. Likewise for the lab-made versions of
diamonds and emeralds. And what does that do to the usual
associations of stone name and colour?
While lab-made diamonds today only get about 1/4 the price of
nature-made, today’s jewelry students might turn that around.
What would the markets say about lab-made diamonds in all colours of
the rainbow?
Red emeralds anyone?
Well my friend, you better line these suckers up as Sapphires were
never meant to look as good as diamonds. I’m sure they call these
stones Cubic Zirconium’s I just mentioned to Peter that a company
will bring a manmade diamond to market to rival the best of the
diamonds to be created by man so far. You know, like a Megabit verses
the old film camera. There are those in the old film school who would
never concede that happening, well bingo!! Digital is here to stay,
and soon manmade diamonds will beat anything mother nature could ever
think up. I’m sure you’ve cut some fine Sapphires, but to compare
them to diamonds, don’t think so sorry. I’m not a master cutter but I
can hold my own.
Thanks, this was fun.
Mark
Unless the color comes from chromium it's not designated as ruby.
So besides chromium, what else occurring in nature can cause corundum
to be red?
Jerry in Kodiak
Peter,
You are getting close to the truth of manmade diamonds. Not only are
they real in every way as diamonds, they’re adding Boron to the clear
diamonds to make them conduit a charge for future use in cell phones.
Like I said in a past post, there’s a company coming out with a real
diamond this year that will be VVVS E F color. I can’t wait to see
DeBeers try and sort this out. Just think of the people who’ll be
able to pay $8000.00 for a perfect diamond, versus $20,000 to
$40,000. DeBeers can go back to selling cocaine