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 Post subject: Used equipment
PostPosted: Sun Sep 25, 2011 1:20 pm 
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As a newcomer to the study of gemology I have been searching in my locality and online for some good secondhand instruments.
Nothing! Where are the retired jewelers and gem students who have quit the business and have equipment lying around unused? Keith :(


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 Post subject: Re: Used equipment
PostPosted: Sun Sep 25, 2011 3:16 pm 
Keith Oliver wrote:
As a newcomer to the study of gemology I have been searching in my locality and online for some good secondhand instruments.
Nothing! Where are the retired jewelers and gem students who have quit the business and have equipment lying around unused? Keith :(


Hi Keith,

I think that many arrange sales privately to those they already know. E-bay is the best way if finding stuff - or, if you are interested in something in particular, you could always place a 'wanted' notice in the appropriate section on this board.

Anywhere between one and many examples of the following have been put up on E-bay in the last year:

- Gemmological microscopes.
- Spectrometry equipment.
- LW/SW UV units.
- Diamond grading lamps.
- Gemmological refractometers
- Polariscopes.
- Balances
- Cameras suitable for photomicrography and macroscopy
- Cheap gems suitable for studies as opposed to prize specimen collection.

Amazon has a good throughput of expensive gemmo textbooks secondhand, some, sometimes, for under 5 bucks!

Which country are you located in? Which items/books are you interested in?


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 Post subject: Re: Used equipment
PostPosted: Sun Sep 25, 2011 7:06 pm 
See here:
http://www.ebay.com/itm/VINTAGE-GEM-DUP ... 3Currently at USD 266 for the pair and only 21 hrs left......


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 Post subject: Re: Used equipment
PostPosted: Sun Sep 25, 2011 11:46 pm 
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Thank you, Cascaillou,for your advice on quality equipment. Keith


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 Post subject: Re: Used equipment
PostPosted: Sun Sep 25, 2011 11:48 pm 
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Location: San Francisco
I'm confused.
What information on quality equipment? Where is it?


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 Post subject: Re: Used equipment
PostPosted: Mon Sep 26, 2011 6:06 pm 
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I have been collecting gemologically useful equipment since about 1970.
Prior to getting connected to the internet in 1998 or so the only things I found locally were as follows:
1) Pieces of scientific equipment that ended up surplus such as obsolete balances and non gemological stereo microscopes.
2)Miscellaneous jewelers tools that retired machinists had used and ended up being sold by their kids in the paper when they died.

I never saw a used refractometer or gemolite in the paper.

All this stuff is widely available on ebay new and used and all the time. There is no other source that is even worth mentioning that I can think of.


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 Post subject: Re: Used equipment
PostPosted: Mon Sep 26, 2011 8:17 pm 
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Joined: Sun Jun 28, 2009 9:56 am
Posts: 991
Quote:
I'm confused.
What information on quality equipment? Where is it?

Lol barbara ...that is a secret. I wispered.

More seriously, here is what I had to say:


Acquiring gemology equipment is quite an investment (and keep in mind that there will be shipping cost, and possibly custom fees, that will increase the final bill).
You can still buy used equipment, but whatever you do, stick to quality instruments. I mean better spend a little more money into some good quality tools, new or used, rather than wasting your bucks into junk that will turn out to be inadequate so you'll end up replacing it. Also, if you want to carry your equipment in the field, pocket sized tools are the way to go.
Here's my personal choice of brands for portable tools (and why):

10x triplet loupe (achromatic and aplanetic):
Belomo 10X triplet loupe. It's cheap (under 30$ brand new) but still very good optics, I like the large diameter lense (bright image and less eye strain).

Calcite dichroscope:
I like the RosGem dichroscope, I know it's an expensive one (135$ brand new), but I really like the large sized squared windows (easier to distinguish close shades)
Note that you could also easily build a filter dichroscope yourself for cheap using linear polarizing filter sheets (however calcite dichroscope is much better than filter dichroscope)

Pocket spectroscope:
for beginners, diffraction grating spectroscope is easier to use than prism spectroscope. I would suggest OPL pocket diffraction grating spectroscope (well known for its quality and ease of use to the beginner, it's about 70$ brand new)

Pocket polariscope:
I like the Gem-A portable folding polariscope (folded it is very small, unfolded it is big enough for stones that have some real size to speak of and still allow use of a conoscope on top of the stone. It's 55$ brand new).
Gem-A also supply (separately) a led light base which fits the polariscope.
Note that you might also choose to build a polariscope yourself for cheap using linear polarizing filter sheets (and why not build it so to it would fit your microscope in order to turn it into a polarizing microscope).

Conoscope:
this is very cheap tool (10$), I prefer the large diameter (1cm) spheres to the tiny ones (easier to use I think).
Note that you might also use your 10x loupe as a makeshift conoscope.

SW/LW UV portable lamp:
model UVSL-14P mini Uv lamp (made by Uvp, and sold at about 75$ brand new), it is weak (only 4Watts) but I like that it is both SW and LW (filtered) in a small sized package. Better get UV protective goggles too (about 10$) as SWUV are very dangerous to your eyes. Polmanminerals.com has all of this.
Of course, if you don't care about portability, better go for a viewing cabinet with more powerful lamp.

Light source (for illumination of stones and for using the spectroscope):
people usually go for the 'mini-maglite R6' (about 15$), which is just fine for illumination of stones. But for spectroscopy, I prefer the 'Gemo Light 3cell' (it's pocket sized, and it has powerful pin-point illumination similar to a fiber optic which is very practical for spectroscopy). Whatever you buy, make sure to get halogen light bulb, not LED. Buying a few replacement light bulbs for your flashlight is also a good idea.
Of course, if you don't care about portability, I'd also suggest a 150W fiber optic halogen light source which will be quite useful for microscopy (I got a used Fostec DCR III illuminator and light guide from fleebay at a very reasonable price)

Tweezers:
I choosed to go for titanium tweezers (rather than steel) as these are non-magnetic (magnetic stuff mess with electronic scales during SG readings). These are about 20$ brand new.

Hardness testing set:
you need nothing but a flat piece of copper, a flat piece of glass, and a flat piece of quartz (4x3cm rectangular pieces will be just fine).

Chelsea filter: you don't really need one (although it might occasionally help with detection of some dyes). But if you want one, choose one featuring a metallic casing (not fragile plastic casing)


This was the cheap part of the story. Now let's talk about expensive gemology tools which are milligram scales, refractometers and gemological microscope.
These can range from under 150$ for junk, to over 1000$ for top quality laboratory tools. My point is that I don't buy junk which I will end up unsatisfied with the quality, but as I want equipment that I can bring in the field (where equipment might possibly end up broken or lost) I don't go for the most expensive stuff neither.

Pocket electronic scale (for weighing stones and for specific gravity measurements):
I own both a 200x0.01g scale (which is cheap, has large capacity, but isn't accurate enough for measuring SG of tiny stones), and a 20x0.002g scale (which is very accurate but has very limited capacity). This is why I bought two different scales. Both feature a calibration option, of course.
Concerning the brand, I'm a firm believer in Tanita scales because they make pocket sized models known for their excellent accuracy, which is hard to get in the world of pocket scales. I highly recommend the Tanita 1230 (20x0.002g) which is a bit pricey (200 to 250$ brand new, best price on miniscale.us) but it is well worth it: very reliable and accurate (calibration weight is included). I also bought the Tanita 1579D (200x0.01g) at 90$, I'm also quite happy with this scale, but it's not the most compact 0.01g pocket scale around, and calibration weight is not included so I had to buy one separately (at 80$).
Personally, I would not buy a used scale from fleebay: electronic scales are fragile instruments that can't handle much wear, so better go for a brand new one rather than loosing money into a used one that might suffer from accuracy issues.
Of course, if you don't care about portability and if money isn't a concern, just go for a laboratory scale that is legal for trade (see Mettler, Sartorius, Ohaus).

Specific gravity kit that will fit your scale(s):
there are some 'universal specific gravity kits' available for sale, but these are bulky, and a bit expensive(80$). So I decided to build my own one for cheap (maybe 15$): it's much smaller than the commercial models, allows higher capacity, and perfectly fits my scales. I've explained how to make one on the forum, here: http://gemologyonline.com/Forum/phpBB2/ ... 11&t=11405

Refractometer (with built in monochromatic yellow filter):
good quality refractometers can be expensive, so it's up on you to choose a refractometer from a reputed manufacturer (will be over 400$ brand new), or a cheap low quality one under 100$ (brand new).
I went for a cheap china-made one (model CL-181) so if it get's broken in the field that's no big deal, however if you do so, make damn sure that the supplier will take it back if calibration is wrong (which you can check using a cheap flame-fusion synthetic blue spinel). Also, these cheap refractometers are supplied with very bad quality RI fluid that you'd better replace. Overall, if you get one that is correctly calibrated (not all are), you should be fine with it, and I like that these are small sized.
Rosgem refractometer is better quality, also small sized, but it's way more expensive (625$ brand new), I've read good things about this one but never tried it myself. At the same price, the Eickhorst is also high quality (I've tried and liked it), only slightly bigger sized.

Gemological microscope (with darkfield and iris diaphragm):
I went for a cheap Gemoro Elite 1030PM (under 250$ brand new +shipping cost and custom fees), sure it's not top of the line but it's fine for the low price. Of course you might prefer to go for a used Gemolite from fleebay (these usually sell for over 500$ but it's great quality).
Actually, the main drawback with the Gemoro 1030PM is that the scope objective doesn't rise much so you cannot focus on the surface of any object exceeding 2cm in height (let's also mention that the darkfield light is only 10Watts which is weak, but it has been suggested that one could just replace it by a 20W bulb to improve luminosity a bit)
If money isn't a concern, then you might have a look here: http://www.gemproducts.com/microscopes.html

At last, let's note that one will need an accurate and exhaustive gemstone reference data book, and I strongly suggest the following book: Tables of gemstone identification, by Roger Dedeyne & Ivo Quintens (around 90$)

Of course, one first need knowledge about how to properly use these tools and how to interpret the results, which requires both theoretical learning and practical experience.


Last edited by cascaillou on Mon Feb 10, 2014 12:13 pm, edited 35 times in total.

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 Post subject: Re: Used equipment
PostPosted: Mon Sep 26, 2011 9:41 pm 
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Joined: Sun Oct 16, 2005 12:22 pm
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Location: San Francisco
Thank you, Cascaillou,for your advice on quality equipment. Barbra :wink:


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 Post subject: Re: Used equipment
PostPosted: Tue Sep 27, 2011 11:46 am 
Kerensky wrote:
See here:
http://www.ebay.com/itm/VINTAGE-GEM-DUP ... 3Currently at USD 266 for the pair and only 21 hrs left......


Just knocked down for USD 395 for the pair. Not to Keith it seems. 12 bids between three bidders. Anyone we know?


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