Gem microscope, suggestions?

[ger100]

I am a newbie, and am getting stuck on several gems. I''ve got some basic tools, but sometimes they conflict. For example, 2 pretty pale pink stones say sapphire by SG, RI, nice reaction under UV, but they are mono-color on dichroscope. I''m suspecting diffusion treated (am I right?). I believe that the way to tell this is under a microscope (am I right?).

What is a reasonable microscope for someone like me? what do I need, like, 2 light sources, dark field, etc.? I have not had my hands on a microscope in 30 years! What should I look for? Price cannot be outrageous.

ALSO, what is the name of a good BOOK to go with the microscope findings?

Thanks
Ger

 

[mogok]

Hello,
Surface diffusion for a pink sapphire? That would be surprising as to my knowledge there is no "surface diffusion" for pink sapphires or rubies. Most of the time if such thing happen, it is "synthetic overgrowth" but not "surface diffusion".
Using the dichroscope if the stones are light in color the dichoism is possibly too weak to be noticed, also keep in mind that in sapphire the dischoism will change with the direction meaning that in some direction you will not see any dichroism.
Regarding inclusions, I all the time advise to people willing to get some knowledge the books I used myself when I was studying gemology: "The photoatlas of Inclusions in gemstones" by Dr E.Gubelin and John Koivula.
They are excellent reference books to use near a microscope.

All the best and enjoy,

 

[Barbara]

Hi Ger,

Vincent is so right when he points out that pale stones in pleochroic species may show the effect so weakly that a dichroscope cannot help you.

GIA sells reconditioned older microscopes through their "gem instruments" arm. Try searching your local newspaper classifieds or ebay for used scopes too. When I started I bought a new, inexpensive, scope and rapidly found out that it wouldn''t do what I needed it to do, so I ended up selling it and getting a Baush and Lomb Gemscope. I found it via the newspaper advertised by a GIA student who had bought the whole equiment package and then decided gemology wasn''t his thing. I got it for about 1/2 of the new price.

In addition to the wonderful book Vincent mentions (and not to be even considered in the same league or mentioned in the same breath): Here''s a link to a simple overview of magnification tools and what you can see with them that I use in my basic gemology class.

http://www.bwsmigel.info/Lesson5/DE.Magnification.html

The diffused blue sapphires of a generation ago are easy to ID with a microscope but the new deep diffusion types defy this method, and in most cases and require lab ID.

Barbara

 

[ger100]

Hi Vincent,

Thanks for the book recommendation. I found 2 volumes online (Vol 1 & 2), both on the pricey to ridiculously pricey side, since they are apparently OOP. Do the 2 volumes complement each other? Does one need both of them?

Ger

 

[ger100]

Wow, Barbara, almost 30 pages of info. "Thanks" doesn''t seem like enough to say in response.

And I just checked your site, with the articles on individual stones...fantastic. I got through maybe a dozen, and must return for more of your little "pearls" as one of my college profs used to call things like this.

Ger

 

[Richard Sherwood]

Kassoy has some interesting inexpensive scopes, including this AccuScope that has zoom up to 45x, $1100. Some 30x scopes quite a bit cheaper.

http://www.kassoy.com/scopes02.html

60x and up is going to cost you a bit, even in the more inexpensive scopes.

 

[ger100]

Hi Richard, and thanks.

What do you know about gem holders for microscopes?

I had (for 1 1/2 days) a small Duo-view darkfield loupe with a maglite and metal gem holder. What a disaster. The metal holder did not like small stones. I put tape around the tips, which seemed to help. But then the screw adjustment for ease of swivel went kerplunk loosey goosey. And finally, after only about 30 minutes of use, the light died...and, no, it wasn''t the batteries. Back she went. So...next stop, seriously search out a microscope. But what do you know about their gem holders...a lot of them look like metal!?

Ger

 

[RockDoc]

You could also try taking a snoop at www.gemproducts.com

He does stock some used scopes. But you need to contact him about what he has.

If you have a "serious" interest, don''t short cut yourself on a scope. It is the gemologists "right hand".

If you are looking for a used scope, I''d recommend the American Optics ones. They aren''t made any longer, but the parts are inside gear system is made of metal, as compared with the newer Leica ones that are made of plastic.


Rockdoc

 

[ger100]

Thanks for the leads RockDoc. Everything I do, I do seriously...that is, if it piques my mental curiosity. And gems done done that!

I studied bio/chem in college, then had a B&L (brand like Barbara has) scope for med school. I bought it used, used it with no problems (I''m careful with equipment), then sold it to the next victim. Didn''t lose a penny and got what I needed from it, as I''m sure the next person did. At the time that was one of the best brands, and all I could afford was used. I was beginning to regret selling it (umpteen x umpteen years ago), but in recent research learned that med scopes ain''t gemscopes. So...

Thanks!
Ger

PS: As a kid, my brother and I were "rockhounds" in West Paternson...Prehnite, Pectolite, Serpentine, lots of Quartz, Amethyst, maybe Actinolite (?) or Aventurine (?), can''t remember what else was there. But I remember someone saying that it was a geologically "special" area. We hunted for "Herkimer Diamonds" in NY once.

We also went to NJ lake country when they drained the Franklin Lakes to pick up Willemite, Franklinite, Zincite, Calcite chunks which had fallen off barges in the 19th century (!)...when they used to haul the stuff through a series of canals (only remnants at that time) to NY (?) plants to extract the zinc...I think it was for the zinc (memory fuzzy...long time ago). That''s when I learned about using a UV light. Guess the circle is coming round.

Too bad my brother sold most of the stuff when my father died...there were literally tons of it. A lot of it came from trading the Franklin Lake material for other rocks with folks all across the country. More than you needed to know, I''m sure.