Joined: Wed Jan 14, 2015 3:52 pm Posts: 576 Location: N Dakota
I was recently given 2 stones about the size of your thumbnail. They thought they might be color change Apatite. In natural light they are a yellowish green. Not sure if I can see a change in color at all. Maybe a bit more gold than green but I'm not sure. What should I expect to see from a color change Apatite? Under what light.
Joined: Wed Jan 14, 2015 3:52 pm Posts: 576 Location: N Dakota
Well that was my thought too, skepticism is my strong suite. I'm starting my last class for GG this month. Colored stone ID and will probably take the lab in the spring. If I haven't figured it out by then I probably need to choose a different profession. By the way your practice stone set is great fun. Even got my oldest son to look at a few. I claim poor eyesight and he pops in to verify readings. He knows what I'm up to but plays the game anyway. Getting better with my instruments and understanding a bit more each time. Thanks Barbra.
I think that almost anything in this color range (slightly greenish yellow) will shift at least a little bit, between purer gold in incandescent light and a greener gold in LED light. I would bet that you could see similar results from most of the classic Durango apatites. IIRC Arya has a synthetic apatite with a significant color change though.
Joined: Fri Mar 18, 2016 4:39 am Posts: 6 Location: China
I have some apatites from Kazakhstan, it change color from light yellow to orangish pink. This color change apatite have been recorded in Gems & Gemology, 2002 Winter.
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
Some years ago we discussed SYNTHETIC color change apatite: G&G, Winter 2010 SYNTHETIC GEM MATERIALS IN THE 2000s: A DECADE IN REVIEW describes:
Quote:
A synthetic apatite with a color change from purple pink in incandescent light to violetish blue in fluorescent light was reported by McClure (2001). While most of the gemological properties were consistent with natural apatite, suspicion arose from an unusual spectrum (seen with a desk-model spectroscope) that was different from natural material. EDXRF analysis showed that the synthetic apatite contained a significant amount of neodymium and a small amount of strontium. Magnification revealed chevron-type growth and elongated gas bubbles, features that strongly supported a synthetic origin. While synthetic apatite is an oddity in the gem world, it has previously been reported for laser applications (Koivula et al., 1992).
IMO, the additives neodymium and strontium would technically classify it as an artificial product
I have some apatites from Kazakhstan, it change color from light yellow to orangish pink. This color change apatite have been recorded in Gems & Gemology, 2002 Winter.
Joined: Fri Mar 18, 2016 4:39 am Posts: 6 Location: China
I just got a 6.4ct color change apatite from cutter. It change color from light yellow near colorless to light pink. And the color changing of rough is stronger than the faceted gemstones. The photos I taken is not so exact to show its color.
Attachments:
File comment: 6.4ct faceted apatite in incandescent light
IMG_20180326_031950.jpg [ 154.06 KiB | Viewed 2054 times ]
File comment: 6.4ct faceted apatite in daylight
IMG_20180326_031930.jpg [ 140.01 KiB | Viewed 2054 times ]
File comment: apatite with muscovite and smoky quartz in incandescent light
IMG_20180320_161449.jpg [ 331.47 KiB | Viewed 2054 times ]
File comment: apatite with muscovite and smoky quartz in daylight
QQ图片20180327132457.jpg [ 302.75 KiB | Viewed 2054 times ]
Users browsing this forum: No registered users and 6 guests
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot post attachments in this forum