"gem quality"

hi

when people use the phrase "gem quality" to describe gemstones, preferably
diamonds in this case, what exactly does that mean - in regards to clarity?

SI2+ is gem quality?
VS2+ is gem quality?
I3+ is gem quality?

please explain, thanks!

The term "gem quality" is a qualitative, subjective term, not quantitative.
It is similar to the term "ore", which is determined by the profit or loss
if mined and sold at any given time. (If it can't be sold at a profit then
it is not ore.)
What you might consider as industrial, carving, junk grade, someone else
might still use the material as a gemstone. Of course diamond grading comes
as close to quantifying the term as humanly possible, (but who knows maybe
one day Bort will be fashionable and considered a gem quality material by
the folks that are into black

"Lawrence" wrote in message
...
hi

when people use the phrase "gem quality" to describe gemstones, preferably
diamonds in this case, what exactly does that mean - in regards to
clarity?

SI2+ is gem quality?
VS2+ is gem quality?
I3+ is gem quality?

please explain, thanks!

"Lawrence" wrote in message
...
hi

when people use the phrase "gem quality" to describe gemstones, preferably
diamonds in this case, what exactly does that mean - in regards to
clarity?

SI2+ is gem quality?
VS2+ is gem quality?
I3+ is gem quality?

please explain, thanks!



iirc, the diamond grading system (well, the GIA at least) goes like this...

1. IF - internally flawless, meaning not inclusions or blemishes of any
sort when looking under a 10x microsope/loupe
2. VVS - very very slight inclusions (either 1 or 2) meaning it has minute
inclusions that are hard to spot for a seasoned diamond grader under a 10x
magnification.
3. VS - very slight (either 1 or 2). Stones that contain minor inclusions
that are difficult to fairly easy to see under 10x magnification
4. SI - Slightly Included (either 1 or 2, SI3 is not recognized b/c it's
really I1). the inclusions are noticeable and can be detected by a trained
grader to see under 10x magnification
5. I - Included (ranges from 1-3). they are obvious inclusions and easy to
spot under a 10x magnification by a seasoned/trained grader. Furthermore,
sometimes the inclusions be seen without the need of magnification. I've
seen some inclusions right off the bat as the stone was placed in front of
me. Furthermore, some of the inclusions are so large it effects the overall
beauty of the stone.

To the best of my knowledge (and I could be wrong) when they say gem
quality, it means the overall appearance of the stone - cut, clarity, color
and carat.

When I buy diamonds, I tend to go for VVS2 or VS1. Yes, it costs a bit
more, but it's worth it.

CeM

On Mon, 30 May 2005 15:18:12 -0700, in ¸õ "CeM"
wrote:


iirc, the diamond grading system (well, the GIA at least) goes like this...

1. IF - internally flawless, meaning not inclusions or blemishes of any
sort when looking under a 10x microsope/loupe

No INTERNAL inclusions or blemishes. The IF grade allows minor surface
imperfections, such as tiny nicks or scratches, which could be polished out by a
diamond cutter, without significant loss of weight. Some wiggle room there, as
the definition of how much weight is considered significant, isn't given. Certain
other types of surface defects are allowed too, including small naturals on the
girdle, as well as minor internal graining.

2. VVS - very very slight inclusions (either 1 or 2) meaning it has minute
inclusions that are hard to spot for a seasoned diamond grader under a 10x
magnification.

This is sometimes described not as "hard to spot", but "extremely difficult to
see". Means about the same, but emphasizes just how minor these inclusions are,
especially with the VVS1 grade.

3. VS - very slight (either 1 or 2). Stones that contain minor inclusions
that are difficult to fairly easy to see under 10x magnification

If they verge into the "fairly easy to see" range, one has to then begin to ask
just when it's an SI1 instead. The key word is "minor" inclusions. usually these
are at least somewhat difficult to see, at least at first glance.

4. SI - Slightly Included (either 1 or 2, SI3 is not recognized b/c it's
really I1). the inclusions are noticeable and can be detected by a trained
grader to see under 10x magnification

SI2 generally goes all the way to inclusions that are obvious and easy to see,
perhaps even quite dominating to the view of the stone, under 10x. The key points
are that these should not be visible to the naked eye in the face up position,
and cannot be inclusions that significantly affect the durability of the stone
(even a not very obvious cleavage, in the wrong place so as to make the stone more
fragile or harder to set, usually will make a grader think about assigning an I1
grade or lower.

5. I - Included (ranges from 1-3). they are obvious inclusions and easy to
spot under a 10x magnification by a seasoned/trained grader. Furthermore,
sometimes the inclusions be seen without the need of magnification. I've
seen some inclusions right off the bat as the stone was placed in front of
me. Furthermore, some of the inclusions are so large it effects the overall
beauty of the stone.

I1 is generally the dividing point between when you can see the inclusions to the
naked eye or not. If not, and they're not a danger to the stone, it will
generally still be an SI2. So the imperfect (I) grades generally have inclusions
that ARE visible to the unaided eye, or are severe enough hazards to the stone to
warrange downgrading the stone. Mind you, this visibility generally assumes a
trained observer, proper lighting, and an unmounted stone. If any of these are
not present, the viewer might not see the inclusions in an I1. if the inclusions
are actually easy to see with the unaided eye, then generally an I2 applies. And
I 3 are those stones where the inclusions are obvious and objectionable to the
unaided eye, verging into those stones where you not only wonder how they managed
to hold it together to cut the thing, but you wonder why they bothered.

These last, the lower end of the I3 grade, start to get to the point where the
original term this thread asked about, "gem quality" starts to become an issue,
some some of these things hardly deserve the honor of being called gems... Often
one sees inexpensive jewelry set with what are euphomistically called "promo
grade". Technically they are diamonds. But often are so transluscent and cloudy,
that using any sort of clarity grading description is meaningless.


To the best of my knowledge (and I could be wrong) when they say gem
quality, it means the overall appearance of the stone - cut, clarity, color
and carat.

"Gem quality" is one of those terms without a precise meaning. It's meaning, like
much of the old style gemological terminology, tends to be whatever the speaker
wishes it to be at the moment. Useful in general conversation, but not so useful
in precisely describing a gem. More of an emotional term, it suggests that a gem
is of sufficient quality to be used as a gem, or to be identified as a finer
example of a gem. Both these meanings are used, and you'll note they are quite
different.

An example:

A diamond dealer showing you his cut stones may pick out a finer stone and
describe it as "real gem quality" or some such, to mean it's better than the
average. It's a "real gem" of a stone, he might say... You then know he's really
impressed by that stone (and wants perhaps to sell it?) But you know little else
without more detail.

Meanwhile a lapidary dealer may dig out a nice bit of labroadorite, better than
the architectural grade building stone labradorite his store is faced with on the
outside, and showing you the colors, explain that this stuff, unlike the building
ornamental stone, is gem quality labradorite. This does not then mean that it's
the top quality facet grade or anything. Just that it's usable as a gem.

Like I said, a highly variable meaning. Unlike the GIA terms, which have a
precise definition, which can be referred to by anyone, simply by looking to the
organization that came up with the terms and issued a precise definition. That
still doesn't mean everyone uses the terms accurately. There are a lot of people
in the industry who've not actually obtained their gemological training from GIA
itself (either the classes, or the published materials), and some of them
sometimes are less than totally accurate in their use of the GIA terms. But one
can at least, say that there ARE, at the base of it all, those precise
definitions.

Peter Rowe (G.G.)

"Peter W.. Rowe," wrote in message
...
On Mon, 30 May 2005 15:18:12 -0700, in ¸õ "CeM"

wrote:


iirc, the diamond grading system (well, the GIA at least) goes like
this...

1. IF - internally flawless, meaning not inclusions or blemishes of any
sort when looking under a 10x microsope/loupe

No INTERNAL inclusions or blemishes. The IF grade allows minor surface
imperfections, such as tiny nicks or scratches, which could be polished
out by a
diamond cutter, without significant loss of weight. Some wiggle room
there, as
the definition of how much weight is considered significant, isn't given.
Certain
other types of surface defects are allowed too, including small naturals
on the
girdle, as well as minor internal graining.

2. VVS - very very slight inclusions (either 1 or 2) meaning it has
minute
inclusions that are hard to spot for a seasoned diamond grader under a
10x
magnification.

This is sometimes described not as "hard to spot", but "extremely
difficult to
see". Means about the same, but emphasizes just how minor these
inclusions are,
especially with the VVS1 grade.

3. VS - very slight (either 1 or 2). Stones that contain minor
inclusions
that are difficult to fairly easy to see under 10x magnification

If they verge into the "fairly easy to see" range, one has to then begin
to ask
just when it's an SI1 instead. The key word is "minor" inclusions.
usually these
are at least somewhat difficult to see, at least at first glance.

4. SI - Slightly Included (either 1 or 2, SI3 is not recognized b/c it's
really I1). the inclusions are noticeable and can be detected by a
trained
grader to see under 10x magnification

SI2 generally goes all the way to inclusions that are obvious and easy to
see,
perhaps even quite dominating to the view of the stone, under 10x. The
key points
are that these should not be visible to the naked eye in the face up
position,
and cannot be inclusions that significantly affect the durability of the
stone
(even a not very obvious cleavage, in the wrong place so as to make the
stone more
fragile or harder to set, usually will make a grader think about assigning
an I1
grade or lower.

5. I - Included (ranges from 1-3). they are obvious inclusions and easy
to
spot under a 10x magnification by a seasoned/trained grader.
Furthermore,
sometimes the inclusions be seen without the need of magnification. I've
seen some inclusions right off the bat as the stone was placed in front
of
me. Furthermore, some of the inclusions are so large it effects the
overall
beauty of the stone.

I1 is generally the dividing point between when you can see the inclusions
to the
naked eye or not. If not, and they're not a danger to the stone, it will
generally still be an SI2. So the imperfect (I) grades generally have
inclusions
that ARE visible to the unaided eye, or are severe enough hazards to the
stone to
warrange downgrading the stone. Mind you, this visibility generally
assumes a
trained observer, proper lighting, and an unmounted stone. If any of
these are
not present, the viewer might not see the inclusions in an I1. if the
inclusions
are actually easy to see with the unaided eye, then generally an I2
applies. And
I 3 are those stones where the inclusions are obvious and objectionable to
the
unaided eye, verging into those stones where you not only wonder how they
managed
to hold it together to cut the thing, but you wonder why they bothered.

These last, the lower end of the I3 grade, start to get to the point where
the
original term this thread asked about, "gem quality" starts to become an
issue,
some some of these things hardly deserve the honor of being called gems...
Often
one sees inexpensive jewelry set with what are euphomistically called
"promo
grade". Technically they are diamonds. But often are so transluscent and
cloudy,
that using any sort of clarity grading description is meaningless.


To the best of my knowledge (and I could be wrong) when they say gem
quality, it means the overall appearance of the stone - cut, clarity,
color
and carat.

"Gem quality" is one of those terms without a precise meaning. It's
meaning, like
much of the old style gemological terminology, tends to be whatever the
speaker
wishes it to be at the moment. Useful in general conversation, but not so
useful
in precisely describing a gem. More of an emotional term, it suggests
that a gem
is of sufficient quality to be used as a gem, or to be identified as a
finer
example of a gem. Both these meanings are used, and you'll note they are
quite
different.

An example:

A diamond dealer showing you his cut stones may pick out a finer stone
and
describe it as "real gem quality" or some such, to mean it's better than
the
average. It's a "real gem" of a stone, he might say... You then know
he's really
impressed by that stone (and wants perhaps to sell it?) But you know
little else
without more detail.

Meanwhile a lapidary dealer may dig out a nice bit of labroadorite, better
than
the architectural grade building stone labradorite his store is faced with
on the
outside, and showing you the colors, explain that this stuff, unlike the
building
ornamental stone, is gem quality labradorite. This does not then mean
that it's
the top quality facet grade or anything. Just that it's usable as a gem.

Like I said, a highly variable meaning. Unlike the GIA terms, which have
a
precise definition, which can be referred to by anyone, simply by looking
to the
organization that came up with the terms and issued a precise definition.
That
still doesn't mean everyone uses the terms accurately. There are a lot of
people
in the industry who've not actually obtained their gemological training
from GIA
itself (either the classes, or the published materials), and some of them
sometimes are less than totally accurate in their use of the GIA terms.
But one
can at least, say that there ARE, at the base of it all, those precise
definitions.

Peter Rowe (G.G.)



I was going by memory from a diamond grading course I took a year ago
through a GIA extension class. I haven't graded diamonds professionally -
not sure if I could handle so many bright shiny objects in the course of one
day.

I knew someone would set me straight. Thanks, Peter.

CeM

well lawerence;
i've or noel have spent about 2 grand to learn about such stuff.
but i can't figure out how to post here and keep my non hacking agreement
with noel.
peter will tell you.
andy


"Lawrence" wrote in message
...
hi

when people use the phrase "gem quality" to describe gemstones, preferably
diamonds in this case, what exactly does that mean - in regards to
clarity?

SI2+ is gem quality?
VS2+ is gem quality?
I3+ is gem quality?

please explain, thanks!

On Sat, 16 Jul 2005 22:06:48 -0700, in ôõ "Spike"
wrote:

well lawerence;
i've or noel have spent about 2 grand to learn about such stuff.
but i can't figure out how to post here and keep my non hacking agreement
with noel.
peter will tell you.
andy

Andy,

As mentioned in my email to you, (and here in case you don't for some reason get
the email), the above message and your email note leaves me confused. Have you
had postings not show up in the group? If so, I can assure you've I've not been
blocking or rejecting anything from you. Please contact me via email if you've
been having problems posting, and we can try and find a solution.

Peter Rowe
moderator
rec.crafts.jewelry

"Peter W.. Rowe," wrote in message
...
On Sat, 16 Jul 2005 22:06:48 -0700, in ôõ "Spike"

wrote:

well lawerence;
i've or noel have spent about 2 grand to learn about such stuff.
but i can't figure out how to post here and keep my non hacking agreement
with noel.
peter will tell you.
andy

Andy,

As mentioned in my email to you, (and here in case you don't for some
reason get
the email), the above message and your email note leaves me confused.
Have you
had postings not show up in the group? If so, I can assure you've I've
not been
blocking or rejecting anything from you. Please contact me via email if
you've
been having problems posting, and we can try and find a solution.

Peter

I can't help noticing that this happens often using OE. As well as this
post of yours, I have a reply post "Subject: Bracelet inspired by a
thrust bearing" by Mike in Arkansas doing the same thing - not showing the
original post. Web view is fine though.

Is it something in your software settings that need changing?

John





Peter Rowe
moderator
rec.crafts.jewelry

On Sun, 17 Jul 2005 12:45:39 -0700, in ¤õ "John" wrote:

Peter

I can't help noticing that this happens often using OE. As well as this
post of yours, I have a reply post "Subject: Bracelet inspired by a
thrust bearing" by Mike in Arkansas doing the same thing - not showing the
original post. Web view is fine though.

Is it something in your software settings that need changing?

John

John,

If you can find a posting on the net, via web view (such as on Google.com's news
service) that means the posting is corretly posted and has not disappeared
somehow. I have, as moderator, no control over how individual ISP's news servers
handle incoming posts, or even, for that matter, how they handle postings sent to
the group by their subscribers. They are supposed to take those incoming posts
and forward them in email to a centralized set of moderator's relay servers, who's
job it is to keep track of actual moderator's email addresses, and those servers
then forward the post to me. I get it in email, approve or reject it, and if
approved, resend it to my own ISP's news servers. In doing this, it gets new
posting headers, including a new message ID header, so it is in essence a new
posting. But "reference" and "in reply to", and headers like that are retained,
so the structural integrety of the post related to the group listings is
maintained. That means that these posts should then correctly take their proper
place in "threads", if your news reader is set up to show postings sorted that
way. Posting dates in the messages are set (and must be set) to the date I resend
the post to Earthlink's news servers. When earthlink gets the posts from me, they
see the added "approved" header, and then propogate the postings out to the rest
of usenet, and when your ISP's news server gets it, the post should then be
correctly displayed. Normally this works fine, and is the way moderated groups
always work.. But much depends on the way each ISP's news server is set up. Some
few do not correctly handle moderated groups, either dropping posts instead of
forwarding them, or not correctly displaying messages for moderated groups once
they have indeed been approved. As moderator, the only thing I can do about this
is to try and contact the news admin at those ISPs and call the situation to their
attention. Sometimes this works, sometimes not. Subscribers to that ISP can, of
course, do the same thing, and often have more clout because they are paying for
service.

When posts are not showing up in someones news reader, sometimes the error is in
one's own news reader. OE is actually notorious for this sort of thing, since it
does not always give you easy indications as to just how you've got it set up, and
changing the sorting means is easy to do without meaning to, with an errant click
on the header bar when reading groups. If, for example, you've got the display
set to not expand threads, then the only posts you see displayed are those which
begin a thread, not followups. That can be confusing if you don't realize it's
doing it. And I think it's also possible, though I'm not sure, to configure OE to
not show you your own sent postings, presumably on the theory that you already
know what it says? Not sure about that. But check.

The best way to figure out the status of a posting is to first check Google's news
servers. Though somewhat slow to update (so allow enough time for me to recieve
and approve a post, and for Google to then get it and post it on their servers),
they do seem to have a quite robust setup, and so far, it seems to correctly
handle the group's postings. So check there first. If a post is there, then it's
been correctly approved and sent to the group. If it is then not in your news
reader, try doing a search in the group for the message ID header, which you
copied from the listing in Google (requires you to look at the full header set for
the message). See if OE can then find it, and where it's hiding it from you. It
may be necessary sometimes to unsubscribe from the group, clear out OE's database
for the group, and resubscribe fresh, downloading all available headers for the
group again. That will usually be several months worth, a long list, but you
should then be able to see all posted messages that are still on the server.

As to my own software settings, as you can tell from the posts headers, I use
Forte Agent to moderate the group, because it functions as both email client and
news client, and becuase, unlike most such programs, it gives me actual access to
the headers, including the approval header (requires undocumented changes to the
..ini file, but that's easy enough to do.) Agent does seem to have some quirks.
I'm never quite sure just exactly which incoming headers I should be retaining. I
*think* I'm keeping all the right ones, according to other moderators I
communicate with, but who knows. One odd quirk that I know originates in my
software is that some incoming posts display normally when I get them, but when
they make it to the group, the carriage return/line feed characters get turned
into =20 sequences. It's not consistant, and no doubt has something to do with
character encoding character sets between incoming and outgoing messages, but to
date, i've not found an actual answer as to what I can do to change this behavior.
Fortunately, it's only annoying, not fatal, to a message, and if I notice it
happening, sometimes I'll take the time to manually edit out the offending extra
characters when sending a message.

But beyond that, as I say, the problem is likely not with my software settings,
but rather somewhere else in the chain, either your ISP, your software, or one of
the several servers that much correctly handle a post between you're sending it
and you're seeing it again in the group listings.

Hope this helps.

Peter Rowe
moderator
rec.crafts.jewelry

On Sun, 17 Jul 2005 19:45:44 GMT, "John" wrote:

I can't help noticing that this happens often using OE. As well as this
post of yours, I have a reply post "Subject: Bracelet inspired by a
thrust bearing" by Mike in Arkansas doing the same thing - not showing the
original post. Web view is fine though.

Is it something in your software settings that need changing?

No, Mike didn't quote anything in his post. His choice.

--
Marilee J. Layman