Help with Aquamarine - Presidium Gem Tester II

[avantgardejunkyard]

Hello Sellers and Happy Day to All!  I am trying to confirm that a pair of earrings are aquamarine.  I have a Presidium Gem Tester II and I cannot find any information on where this gem would register on the tester.  Is there someone here selling jewelry, aquamarines, that can help me with this?  I have tried and tried to figure it out and I just can't find any information on the web that I can make sense of.  If someone could send me a picture of what you know is aquamarine and how is registers on the Presidium tester, I would really appreciate the help.  Thanks so much everyone!!!

[silverstatetreasureboxes]

@avantgardejunkyard 

I have know idea but I'm thinking of buying one of these testers myself. I do know one of our team members @idealgems1 is a trusted expert in this field, while we wait for him can you post of photo of your Aquamarine?

[idealgems1]

Sorry, no help with the Presidium tool.  As a Graduate Gemologist, the determinative test for aquamarine versus blue topaz, synthetic spinel, or another gem material would be refractive index.  It's a simple and straightforward test, but it does require you having a refractometer, refractive index test fluid, and a monochromatic light source.  Back in the day we would buy our gemological equipment from GIA's Gem Instruments Corporation.  Today, various jewelry tool and equipment distributors also have decent selections.

A strong indicator, but not conclusive proof of aquamarine would be inclusions that are sort of elongated parallel tube-like inclusions.  This is very common in aquamarine but not in similar looking gems.  Even large aquas can be pretty much loupe clean, though.

Another ancillary test would be longwave fluorescence:  strong chalky green fluorescence is a dead giveaway to synthetic spinel.

Sorry I couldn't have been more help!

[frommichel]

Hello. Aquamarine is a beryl. Emerald is also a beryl. On the Presidium II, an aqua would test in the emerald beryl range.

[frommichel · Accepted solution]

Oh, one extra note. Make sure that you wipe with acetone any gemstone just b/f testing it. This will make sure that you are testing the gem and not the oil/dust that might be on the gem (even an invisible amount of oil from touching the gem could interfere with getting an accurate reading).

[jklfindings]

As mentioned above, aquamarine and morganite will test the same as other beryl (emerald) on the Presidium Gem Tester II.  I am a gemologist, I use the Presidium gem tester pretty much daily.  I primarily buy gems and jewelry while travelling, so it's a great little tool to have in the arsenal when an actual testing setup isn't practical.  It's nice to be able to separate topaz from aqua, garnets tourmalines and sapphires, etc, quickly.  That being said.... this is only another tool that shouldn't be relied upon heavily.  Some people are looking for a magic bullet when they purchase this tester, and this is by far not it.  The tester has many downfalls, because it's not meant to be used over other gemological tools.  It's meant to be used in conjunction with basic tools, and a good bit of knowledge.  A lot of the categorized areas on the tester overlap closely, and without gemological knowledge and other tools, you'll still be guessing essentially.  The tester also needs to be calibrated pretty often.  My advice is if you are looking for the best way to ID gemstones, get a refractometer and a polariscope.  That will cover about 90% of everything you will ever need.  If you are already a gemologist who likes new tools, and saving refractometer liquid, try the Presidium out!

[idealgems1]

"My advice is if you are looking for the best way to ID gemstones, get a refractometer and a polariscope.  That will cover about 90% of everything you will ever need. "

I agree 100% but would add also a binocular microscope (or get good at using a loupe).  And you don't have to be a full-fledged gemologist in order to be able use them effectively.  Of course, more knowledge is always better...

[flipping_treasures]

Question, isn't a refractometer primarily for use with loose stones?  Can they be used with set stones?  TIA

[idealgems1]

It will work with most mounted stones too.  If the table (top facet) of the gem is able to go flat on the surface of the refractometer, you're golden.  On most mounted gems, the prongs or bezel will allow that...usually there is only a problem if the crown of the gem is super shallow.

[avantgardejunkyard]

Thank you so much for your advice.  Here is a picture of the earrings in question.  I will run the test tomorrow.

[avantgardejunkyard]

Hello, thanks for chiming in.  I put a picture of one of the earrings because it really shows the color in a reply below this one.  I really appreciate yours and everyones help with this!!!  Blessings and peace to all!!!

[avantgardejunkyard]

A family member passed away and another ready to part with their jewelry.  There is lot of fine jewelry to sell.  I sort of know a lot of gemstones both people had, just because of living with them.  And, the Presidium has been a good tool to say, yes, that is exactly what I knew the stone was because I purchased it initially or when it was purchased I was shown and told what the jewelry was. 

Anyway, I did not intend to be a jeweler, but it seems I am going to have to learn quite a bit.  But, the Presidium is great when you have an idea what you already know what the stone is and it confirms that!  Here is a pretty good picture of the blue of the stone in one of the earrings.  It is the closest to the actual color and I only had one earring.  I do not think this is a blue topaz, but I guess it could be a sky blue topaz.  And, I am not sure of the price difference between the two.  Ugh!!!  Life is full of challenges, and that is for sure!  I would love to get the earrings sold!  Thanks for your chime in!!!

[avantgardejunkyard]

Yeah, I have a black spinel cocktail ring and I could not use the Presidium to test because the prongs are too small and it keeps hitting the mounting metal.   Then you get the buzz of death!!!

[avantgardejunkyard]

Sorry I meant the stones are small...not the prongs...

[avantgardejunkyard]

Thanks to all for your help!!!