Which colored stones are prone to fading in sunlight?

[Dee*Jay]

At the gemshow last weekend Catmom told me to warn one of my friends who just bought an amethyst about the potential of fading, and I started thinking about other stones that might fade in the sun. Any insight here will be much appreciated!

 

[chrono]

I''ve never heard of amethyst fading under sunlight over time but I do know that kunzite does fade from pink to clear white when exposed to sunlight repeatedly thus earning the nickname of the twilight gem (or something like that).

 

[innerkitten]

Amethyst is supposed to prone to fading in sunlight. Such a bummer. And heated Zircon can revert to the color it was before it was heated. Not sure if it has anything to do with sunlight though.

 

[FireGoddess]

Kunzite for sure.

 

[Harriet]

Here's what Schumann says:
"There are some amethysts that lose some color in dalylight. The original colour can be restored by X-ray radation."

 

[lizzyd]

I know that the colors of Green Spodumene (Hiddenite) and Pink Spodumene (Kunzite) can be somewhat unstable, and can fade if exposed to intense light and/or heat over time. I believe the same holds true for some nuked (irradiated) stones.

Here's a good pic of a 28ct. hiddenite and an explanation of the effect. Scroll about 3/4 of the way down the page: http://atggems.com/Photos_Misc2.htm

ETA: I inherited some big stones from my grandfather and recently sent them off to John Bradshaw of Coast to Coast Cutters (he's in Nashua, NH) for analysis and re-cutting. Turns out, two of the three pink stones are kunzite and can cleave so easily that they may not survive the re-cutting process. C'est la vie. They are of no use to me in the condition they are in now, so I might as well give it a shot. Anyway, my Mom always called it the Evening Stone. Come to think of it, I can post the "Before" pictures. There are five. Hopefully there will be five "after"pics too, but there may only be three.


Best,
LizzyD

 

[jewels5]

Hello! I am new to the forum...

Amethyst can fade in the sunlight as can kunzite, rose quartz, irradiated yellow and orange sapphires, some brown topaz, and zircon can return to a light brown if exposed to lots of light.

 

[twodoor2]

I had an aquamarine fade on me. Generally, the irriadiated stuff and some of the heat treated material for kunzite, morganite, and aquamarine, can fade. I also have a deep pink/purple untreated Kunzite, and it never faded. However, as a rule of thumb, I normally shy away from those particular pastel stones since you can never be 100% positive. My amethysts (and I have several) never faded.

 

[Dee*Jay]

Thank you all very much for these replies, and please keep ''em comming! This is very educational.

 

[innerkitten]

Hmmm, wouldn''t want to have a stone under go some sort of radiation every few years. I hve amethysts that have retained color just fine but I don''t wear them all the time.