is this a good idea or am i losing my mind??

[T L]

One should also note that not all cobalt spinels are equal. There are less saturated, and unattractive cobalt spinels and there are fine ones, just like there are super neon copper bearing tourmalines, and ones that look like ordinary aquamarine but the "copper bearing" status makes them $$$$ as far as a dealer is concerned. One must always judge color first and foremost, regardless of the chromophore, and the hype behind the marketing of the gem.

Also beware of listings that state "cobalt blue" spinel, because that doesn't necessarily have to contain cobalt.

 

[Marlow]

TL

You are right - many Co-Spinel ( I never use cobalt BLUE spinel) from Sri Lanka are Cobalto-ferrous spinel. Many have a gray mask ( I know you like this very much!!) - also blue spinel with a fantastic color without cobalt.

I bought 10 from Sri Lanka - 8 with the typical Chelsea Filter Reaction - two were inert. The vendor is a highly respect scientist!!

Dr. Schmetzer checked - 8 are Co, two not - but NOT the two with the inert reaction - so Chelsea filter was 6:4 - never trust this filter.

http://www.johnjbradshaw.com/gemInfo.php?page_id=17

This is beautiful spinel - cobalt spinel and a colorless I missed!

 

[Marlow]

Got an answer from Dr. Schmetzer:

I asked him that the cobalt must be extremely low in this gem.

His answer:

"Yes, the cobalt content is extremely low in such a pale stone that it is not possible to measure it with a microprobe or x-ray fluoresence.
i am interested how they detect the orign" ( that the stone is natural - my addition!)

----

I think that the stone is very interesting and it would be great if GIA could do some research on it!

 

[LoversKites]

Here's an extremely well cut 2 carat white spinel from a recommeded PS vendor. He will do an AIGS lab memo for you for an extra charge. It is highly recommended with colorless spinels as they're commonly synthesized.

http://www.ebay.com/itm/2-08ct-Marvelous-AAA-Oval-Natural-White-Spinel-/331283962947?pt=LH_DefaultDomain_0&hash=item4d22101c43

I saw this -- and I knew it would be posted on PS at some point.