Wednesday, December 3, 2008

Color-Change Stone: Alexandrite? Garnet? Spinel? Synthetic?

Mix of Daylight and Energy Smart Light*

Mix of Daylight and Energy Smart Light*

Incandescent Light (Slightly more red than depicted here)*

Incandescent Light (Slightly more red than depicted here)*

Incandescent Light (More red than depicted here)*

I bought this ring last week at Savage Mills Mall in Columbia, Maryland. The tag said the stone was Alexandrite; I really have serious doubts, but I can see why the seller might think so. However, the price I paid was NOT equal to natural Alex prices--not even close (which is why I was able to afford the ring), so I bought it on the assumption that the stone is NOT Alex, but is likely to be another kind of color-change stone (garnet, spinel, sapphire, or even a synthetic corundum: Worst-case scenario: glass. Yikes!).

Total carat weight of ring: 36.5.

14 KT, at least I think so--I can barely read the mark--but it looks like gold and passes the magnet test. The gold color in the photos is accurate. The metal has a nice "old" patina with some slight scratches on the inside. Could the ring be from the 1920's or 1940's? It kind of looks Art Deco-ish. The ring is dirty (which explains some of those spots on it), and there is some wear along the facets of the window. Obviously, the former owner(s) wore it a lot.

I'm not sure how to clean it safely.

It is solidly set--no loose prongs. Still, I worry. It looks so vulnerable.

I'm guessing the stone is 15-20 carats--it's BIG. Dimensions 14 mm round, 6.5-7 mm deep. "Ostentatious" is a great descriptor, yet it's not a girly-girl ring (part of its appeal to me).

It could be synthetic Alex, but I don't think it's Russian lab; I have a known Russian lab stone, and it's not like the stone in the ring at all. For one thing, the Russian lab is darker; the daylight color is a definite emerald, and the incandescent color is a deep purple, almost a black.

In the above photos, I was (more or less) able to capture the two main color changes. The photos aren't perfect, though; they make the stone look more like blue and purple Tanzanite.

I compared the stone under incandescent light with a known amethyst (deep purple color) stone in an antique gold setting, and my mystery stone had more red in it--more like raspberry.

Try as I might, my camera could not catch the color seen under a mix of fluorescent and daylight: a brilliant London Blue with flashes of aqua, purple, and red--it is really quite breathless. My photos show just blue.

A mix of fluorescent and daylight; unfortunately, my camera could not quite catch the stunning London Blue with aqua, purple, and red flashes*

Other colors:

Clear day, in shadow: bluish, maybe bluish-violet.

Daylight, direct sunlight: pink with blue flashes.

Cloudy day: Medium icy blue/green, a bit like light aquamarine, although a bit darker. Depending on angle of light, sometimes a smoky spot, either in the middle or along one edge.

Setting sun (deep slant): red with purple lashes.
* Note: all photos are un-enhanced; however, they have been cropped.*


Amelia G said...

I came across this post while looking for info on my color change garnet. I would say that's what you have...maybe. ;)

I can't tell from the pics (I haven't been able to get any good ones of my ring either), but your description of the color change in different lights fits exactly with the attributes of my stone.

I'm not a jewelry or expert by any means, but looks like a nice stone you got there. If it is a color change garnet depending on the clarity it could really be worth something. As for cleaning it, again if it is a color change garnet, you can clean it with regular jewelry cleaner - that's what my jeweler advised me to do. In fact, I'm going home to do it tonight because I'm getting married on Sunday and I want my engagement ring (the garnet) to look shiny like my wedding band. :)

Enjoy your stone!

Bugzita said...

Thanks, Amelia, for taking the time to comment on my stone.

No matter what it is, I just enjoy it. It's big and showy ;=)

I just returned from Arizona, where I picked up some great jewelry and minerals (mostly minerals and specimens).

Again, thanks!

Anonymous said...

It sure looks like "color change quartz" to me. That is a synthetic quartz from China. It has some chromium in it to cause the color change effect.

Outdoors it will look like Amethyst. Indoors it will look kind of raspberry. If you look at it with a long wavelength UV source it will glow red. If you use a short wavelength UV source it will glow orange.

Anonymous said...

Sorry, Amelia... while it'd be SUPER COOL to find that you'd come across the rarest Garnet in the world at an extremely cheap price... it's really not likely. The largest stones cut are barely over a carat, and the larger the stone the more murky they appear. "The stone is extraordinarily rare. The rarity increases dramatically above one carat. In my experience most stones over the carat become murky and gray. A fine one-carat would be a find indeed." Direct quote from:

Beautiful gem, whatever it may be... but I seriously doubt that it's a Pyrope-Spessartine (also called the Alexandrite Garnet), I've been looking for that one myself lol

Polly said...

The stone in your ring is a synthetic colour change corundum. I have the same colour stone in my ring.