A few weeks ago I had an interesting email conversation with a new gemology student about a 10 X 8 mm oval stone she had received in a J*V parcel a couple years ago and had set into a ring. This conversation took place over a period of a couple of days and it was really interesting to watch the process she went through to identify the stone.
She started out by sending me these pictures and a brief description of how she got the stone.
The pink and green pics are the same ring in different light sources. It was funny when I first got the parcel I set them up by color in a tray and wondered why I had put a pink in the green section, later looked and it was green in the pink section, then it finally dawned on me that it was a color change stone.
It refracts like glass. The jeweler said it wasn't synthetic because of something with the bubbles (my husband took it to the jeweler) so I am going from what he said and my recall of about 2 years ago.
Yes as I recall he said in glass they are many or uniform or something but I really don't recall much. Anyway he said he did think it was a natural stone. I really have always thought it was a synthetic even though they were insistent that it wasn’t. J*V also suggested I send it to their independent gemologist to be analyzed for $50.00 and had seriously thought about doing it but never got around to it.
I pressed her for more information (poor woman. Remember, she's a new student.) She almost pulled the prongs when I asked her for the SG but she kept the ring intact and still managed to do these tests:
It is clearly 1.52ish much closer to 2 than 3. I used a known amethyst and peridot as a control just to be sure my refractometer was reasonably accurate and they came out in range as listed on my reference chart. I am not great with the dichroscope but think I am seeing 3 colors. Chelsea filter seeing a change to yellowish greenish, from purpleish pink. Inert from SW/LW.
Then there was this:
One other thing. I was thinking since the time I got it and discovered it had such a low RI that it might be Zandrite since that is one of the color change stones they have at J*V. I did call them and asked if it was a possibility that a synthetic stone could possibly get into the parcels and they insisted this was not possible and that the stone was not synthetic or simulated. I even sent the refractometer back thinking it may not work properly and many months later ordered another one and still got the same results.
Talk about due diligence! She sent the refractometer back because she was told it was impossible that there was a synthetic stone in her parcel, and when she did her most recent testing, she used two known stones to make sure her refractometer was giving an accurate reading.
I haven't examined the stone myself, but it sounds to me like she called it correctly in the beginning.
I know she was hoping it was natural, but I think it made a pretty ring, and a great gemology lesson as well!