Corundrum getting darker with age?

[AustenNut]

I was talking with a coworker who has a ruby e-ring (from Burma, I believe). She was saying that her stone has gotten significantly darker over time. When she got engaged she also got a set of earrings made out of the same material. Her earrings (which get occasional wear) are still red-red, but now her ring ruby is so dark that it's almost black. Is this to be expected? Is it common? If this is happening with a ruby does it also happen with sapphires? Is there anything to prevent this from happening (apart from not wearing the stone daily)?

 

[T L]

I was talking with a coworker who has a ruby e-ring (from Burma, I believe). She was saying that her stone has gotten significantly darker over time. When she got engaged she also got a set of earrings made out of the same material. Her earrings (which get occasional wear) are still red-red, but now her ring ruby is so dark that it's almost black. Is this to be expected? Is it common? If this is happening with a ruby does it also happen with sapphires? Is there anything to prevent this from happening (apart from not wearing the stone daily)?

Ummm. . . that's odd. Royal jewels have held rubies for eons, and they don't go black.

 

[Indylady]

Is it just dirty?

 

[VapidLapid]

a) cataracts
b) macular degeneration
c) idealized memory
d) dirty
e) any combination of the above

 

[chictomato]

a) cataracts
b) macular degeneration
c) idealized memory
d) dirty
e) any combination of the above

Haha that's funny

 

[chrono]

No, I have never heard of corundum getting darker with age. It could happen to require some intense cleaning.

 

[Circe]

If it's glass-filled, I could imagine the bonding agent darkening ... or, alternately, if it's been subjected to intense heat, I can imagine the color changing. Just on its own, with the passage of time? No. It's either dirty, or there's something wonky there. Has she ever had it appraised?

 

[morecarats]

As you probably know, ruby is aluminum oxide. Thus it is subject to oxidization.

Just like your car, your ruby can rust if subject to the right environmental conditions. Many consumers are not willing to pay the extra for rust-proofing when they buy a ruby, but it is well worth the extra cost. You should have the pavilion done as well as the crown, since this is the part of the stone that may come in contact with salt from your skin. The next time your dealer offers you options like rust-proofing you shouldn't think of it as just an unnecessary extra that the dealer is trying to sell you to increase his margin. Your ruby will last longer and have a higher resell value if you have it rust-proofed.

 

[chrono]

More Carats,
What is done during this “rust proofing” process? What does it entail, chemical used, how long it lasts, etc?

 

[morecarats]

You probably know that ruby is colored by chromium. Just like the chrome trim on your car, chromium provide corrosion resistance. If you ruby does not have enough chromium it is more likely to rust. So the rust proofing process will increase the chromium level to increase the corrosion resistance. Just remember, in the words of Neil Young, "rust never sleeps."

 

[colormyworld]

As you probably know, ruby is aluminum oxide. Thus it is subject to oxidization.

Just like your car, your ruby can rust if subject to the right environmental conditions. Many consumers are not willing to pay the extra for rust-proofing when they buy a ruby, but it is well worth the extra cost. You should have the pavilion done as well as the crown, since this is the part of the stone that may come in contact with salt from your skin. The next time your dealer offers you options like rust-proofing you shouldn't think of it as just an unnecessary extra that the dealer is trying to sell you to increase his margin. Your ruby will last longer and have a higher resell value if you have it rust-proofed.

Very funny stuff there morecarats. I think some would be surprised to learn that corundum is actually aluminum "rust" in crystal form.

 

[AustenNut]

Thanks for all of the replies so far. So it's either:

1) Faulty memory
2) Something wonky with her stone (perhaps filled with something)
3) Didn't receive/in need of a rust prevention treatment with chromium

Forgive my ignorance, but are both sapphires and rubies made of aluminum oxide, or is aluminum oxide the agent that makes rubies red? Neither the person I bought my stone from nor my jeweler has ever mentioned the rust prevention treatment.

 

[vinkalmann]

More Carats,
What is done during this “rust proofing” process? What does it entail, chemical used, how long it lasts, etc?

I think TC is playing a game based on the rust-proofing that car dealers try to up sell you on when you buy a car. Total unnecessary gimmick of course. No way that this stops a car from rusting (or a sapphire/ruby).

 

[vinkalmann]

Thanks for all of the replies so far. So it's either:

1) Faulty memory
2) Something wonky with her stone (perhaps filled with something)
3) Didn't receive/in need of a rust prevention treatment with chromium

Forgive my ignorance, but are both sapphires and rubies made of aluminum oxide, or is aluminum oxide the agent that makes rubies red? Neither the person I bought my stone from nor my jeweler has ever mentioned the rust prevention treatment.

If I'm not mistaken, it's the addition of trace amounts of titanium that make sapphires blue, and it's trace amounts of chromium that result in rubies. Both sapphires and rubies have crystallized aluminum oxide (corundum) as the base.

 

[StonieGrl]

VapidLapid, heehee, right on the monay!!!

Re rustproofing: And don't forget the scotchguarding and window tint!

 

[chrono]

DUH! Ok, I get it now. MC is only pulling my leg as I’ve never heard of such a thing. That’s what I get for taking things literally.

 

[vinkalmann]

VapidLapid, heehee, right on the monay!!!

Re rustproofing: And don't forget the scotchguarding and window tint!

LOL..."Window Tint". Got a windowed stone? Try a Window Tint.

 

[dzop]

MC is kidding, but there's a grain of truth in there.

Corundum is -resistant- to weathering. It is not weathering proof. Given enough time and exposure to water, it will alter to mica-- I think, most commonly, to margarite. But this process operates on geologic timescales, not over the length of a marriage, however long a time that might seem.

See picture below, from corunduminium, of a sapphire altering to margasite:

 

[AustenNut]

Ok, at first I thought the rust proofing was a gimmick but started believing it when Chrono was taking it seriously. Apparently we're both gullible. So basically the gist is that a genuine piece of corundrum won't be affected by exposure and that something's funky with my co-worker's stone. Glad to know that my e-ring shouldn't be changing colors on me!