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 Post subject: So lets talk about Raman...
PostPosted: Mon Sep 07, 2009 7:16 pm 
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Is raman spectroscopy going to be available to people with normal wallets?

And are there any catches in using them for gem identification? (what I hope to be a rhetorical question) :)

Curious!


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PostPosted: Mon Sep 07, 2009 9:08 pm 
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Quote:
Is raman spectroscopy going to be available to people with normal wallets?


One day in the future probably. In the near immediate future no.
No seems to be able to stuff the price below about $20,000 or so.

But as my wealthy uncle used to say forecasting things is hard especially when you are talking about the future.

For example the Blu Ray Disk player has propagated 405nanometer lasers diodes. and since the ccd sensors are being made by the ton for everything from cellphone cames to other better cameras such instruments might achieve the economies that come with mass production.
If for example homeland insecurity decides every police officer needs one on his holster belt. That would be good for gemologists.

But don't be holding your breath while you wait.

Quote:
And are there any catches in using them for gem identification? (what I hope to be a rhetorical question)


No more than the usual catches. Which is to say, for most people, the catch would be, approximately a masters degree in analytical chemistry or geology. Raman spectroscopy is not a beginners technique.

No one has published a how to for gemologists. Everyone who does it uses techniques that are specific to the particular instrument they have.

What is it, you are interested in looking at??


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PostPosted: Mon Sep 07, 2009 9:25 pm 
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Apparently Enwave (and others) have 785Laser Raman new for just under $10K. Don't know if this qualifies for normal wallet, but if you are in the lab business, it is worth looking into.

G4 is right, in that you want to define Raman a little bit closer. You can get Raman photoluminescent reactions with a blue or green laser and a regular spectrometer. Quite possibly for under $4k. But what you are really missing is the Raman anti-stokes readings to get the signature for the (other half) of the Raman stretch.

And also true, you may get to see a lot of squiggley lines, peaks and valleys, but it is the interpretation of this data that is a true bugger. Some of it you can. THere are even programs to help you along in identifcation. Some data even coincides with certain infrared ranges in that you are looking at molecular stretch coordinates. But be my guest to try and interpret it all without an advanced science degree.

Bear


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PostPosted: Mon Sep 07, 2009 10:08 pm 
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4k? :? 10k!? Twenty! :shock: Drat! 'Thought one could buy a chunk of quality time with one of those for a couple' hundred...


[Note: I've been digging my long-lost humor lately. Give it a little while and it'll show why it got under in the first place... ]

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PostPosted: Mon Sep 07, 2009 10:15 pm 
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I think if one needs a gemstone to undergo (is that the right word?) a Raman, it would be less expensive to send it to a lab that has both the instrument and a person to decipher the results.

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PostPosted: Mon Sep 07, 2009 10:24 pm 
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Morning Dove is quite right about that. You would really need a pretty massive flow of material to really justify such an expenditure.

Where I work we are about to purchase an FTIR microscope and a Raman Microscope. My name is on the grant as the operator and maintainer of the instruments. Stay tuned. :twisted:


Last edited by G4Lab on Tue Sep 08, 2009 1:10 am, edited 1 time in total.

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PostPosted: Mon Sep 07, 2009 10:36 pm 
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Very nice G4. We've been operating a raman for a couple of years here and we're very pleased with the results. With the rruff program we are also able to make fairly quick diagnostics. Our lab charges only $15 for a raman test, so this does make the cost affordable for those who don't want to go out and spend $20k.
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PostPosted: Tue Sep 08, 2009 4:27 am 
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Quote:
Our lab charges only $15 for a raman test


Bear, are you able to ID inclusions as well with your set-up?


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PostPosted: Tue Sep 08, 2009 8:26 am 
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Tim,

Ours is not a micro Raman. I have however, with the help of an optivisor; focused in on certain inclusions in various stones and identified them. But our unit is mainly for general materials id.

As Bill H. implied regarding Raman tests, ".. killing a mosquito with a cannon". I agree that we don't want to stray too far from conventional equipment, but when I already have this machine on, I can get results in under a minute without the use of poisonous chemicals. :smt063


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PostPosted: Tue Sep 08, 2009 8:35 am 
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Bear is doing the gemology public a great service crank up that instrument for $15.

As some of you may know a number of labs that charged alot more have closed their doors after hemorrhaging money for years even when the economy was better.

I like the idea of using an optivisor lens to focus you beams. Something I would do. And I suspect Dr. Bill H as well.


Last edited by G4Lab on Tue Sep 08, 2009 8:37 am, edited 1 time in total.

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PostPosted: Tue Sep 08, 2009 8:36 am 
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maybe one micro Raman will come up in a certain liquidation sale soon... 8)

Re: mozzies and canons....

it does kill 'm...


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PostPosted: Tue Sep 08, 2009 9:03 am 
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Has anyone here used the portable or hand-held raman units?


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 Post subject: I just want to say...
PostPosted: Wed Sep 09, 2009 4:26 pm 
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...that I love this forum! :)

As a not so experienced gemaholic Raman always sounded as the easy future way to id a stone.

Good to hear the voice and opinions of people working with it.


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PostPosted: Thu Sep 10, 2009 12:19 am 
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If you want to be good at anything in life you need to know what you are doing. I just got off the phone with Marty Haske who was bludgeoning me about a point of calibration in UV VIS spectroscopy. The basic technique. I suggested he get together with Brian and see whether they can work together on the question. I didn't take advanced enough mathematics to jump into that particular question.

Raman and FTIR are much more complex in every aspect. The equipment, specimen positioning, the data sets, and the interpretations thereof.

I have been interested in gemology long enough to see a number of processes that people wanted to automate. The great majority of them did not catch on.

I am confident that we will see wonders in the future since sensor chips are so widely used in consumer products and computing power is free and becoming massive even in a cellphone.

But I don't think we need to furlough all the trained gemologists just yet.


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 Post subject: Raman types?
PostPosted: Tue Oct 06, 2009 5:03 pm 
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I prefer beef to chicken flavored Raman.... winstone


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