need you help~do you think these sapphires are treated?

[babydoll_mini]

Hi hi experts~ I need your opinions, please help me decide whether to set these little 5 sapphires.

I bought them at the recent Shanghai Jewelry Fair, from a Sri Lanka trader actually, for 500 rmb (= 73 US dollars).
They are 1.5 ct in all, and the largest one is approximately 4mm in size.
I am considering to set them into a five-stone band, which will cost me about 1000rmb, twice the price of the stones

But I have a concern that these stones might have had severe treatments beyond the basic heating.
I know it is (almost if not at all) impossible to tell whether a stone is treated or not by a picture.
But from the price and the carat weight, and considering the cost of treatment, do you think these stone have been BE treated or anything else?
If it is very much likely that they are very heavily treated, I''d rather leave them as they are and save the money of setting them.

Thank you all in advance!

 

[chrono]

You are correct that the sapphires are very likely to be treated beyond the standard heat treatment, based on the very inexpensive price (15USD for each 0.3 ct, 4 mm stone). There is also the possibility of them being synthetic or something else.

 

[babydoll_mini]

Chrono, thank you for your reply! I am thrilled. You are one of my PS idols

I had a lab guy from NGTC (Chinese version AGL, but not as authorized of course) to check the stone for me briefly at the jewelry fair.
But he did not have any advance equipments except something looked like a huge microscope with sophisticated lights.
He said there''s not much he can tell without necessary equipments, but with the microscope, he didn''t observe anything wrong.
So my guess is that these are corundum, but the treatment...who knows.

I''m just curious, are the advanced treatments, like BE or radiation so inexpensive? That they can still make profit at such a low selling price?

 

[chrono]

Information on BE treatment of corundum. http://lgdl.gia.edu/pdfs/su03a1.pdf

As you can see, it takes very specialized equipment (aka expensive) to be able to detect beryllium diffusion, and even so, will produce minor pitting in the process. The older method of diffusion where the colour is only on the outer layer is easy to detect via an immersion test, but the new diffusion method where the colour goes all the way through is a different matter altogether.

Very very dark blue sapphires are diffused, then heated again to get a medium dark to dark blue colour. My guess is that since the original gravel quality material is practically worthless to begin with, the profit margin covers the apparently low cost of the high heat treatment w/beryllium added, especially since the heating is done in bulk.

PS
Babydoll, I''m easily embarrassed.

I''m just a regular long time poster who''s seen/handled many gemstones and happen to read a lot as well.