Sun Colored Amethyst questions

[Graydigger]

I understand how bottles become colored amethyst, but have a few questions:
-How long does it take (with full exposure) for a bottle to turn amethyst (months/years)?
-Can this be done through a window pane , bottles placed in window?
-I have dug a few old bottles that were amethyst. How did this occur if buried?
-With the modern process of X-Ray (or whatever) to color bottles, why do they let the process continue until the bottle is unnaturally very dark purple--why not stop it so the bottles at least look naturally sun-colored? Any answers are appreciated. Thanks

 

[sweetrelease]

most likly the best question asked this year!! i have no idea but have thought the same thing,good question,matt

 

[Oldtimer]

ORIGINAL: Graydigger

I understand how bottles become colored amethyst, but have a few questions:
-How long does it take (with full exposure) for a bottle to turn amethyst (months/years)? 3-4 years will give a nice tint, 10 will give you a nice SCA color.
-Can this be done through a window pane , bottles placed in window? Yes.
-I have dug a few old bottles that were amethyst. How did this occur if buried? The sands of time covered them after they had turned...
-With the modern process of X-Ray (or whatever) to color bottles, why do they let the process continue until the bottle is unnaturally very dark purple--why not stop it so the bottles at least look naturally sun-colored?
Some people have no taste...lol...
Any answers are appreciated. Thanks

 

[cobaltbot]

Here’s some opinions, more or less factual:

How dark natural amethyst looks depends on proper exposure and the amount of manganese in the glass batch. Some people actually prefer to keep the items clear and not let them turn and this is understandable, like in the case where all known examples are amethyst or colored and clear examples are limited. Outdoor or light box exposure should do most all of what it’s going to do in weeks – months beyond that you have to get into the radiation stuff which although a lot of newbies and non-collectors like most collectors don’t, thinking it an unnatural or altered item. Very little, if any turning will happen inside on a window sill as most of the UV rays do not get thru to the bottle. Some bottles that you dig could already be amethyst for a few reasons. For one, those bottles may have been out in the sun during their use. They might have been covered up after being surface trash. They might have been intentionally or unintentionally produced in amethyst because of heavy amounts of manganese and/or other ingredients in the batch. This very dark crown top most likely made by the American Glass Works in Richmond VA or at Paden City, WV is one of my favorite sodas, partly because I found it when I was a kid. I’m not sure if it turned, or was already this color when it was new.

 

[GuntherHess]

-How long does it take (with full exposure) for a bottle to turn amethyst (months/years)?

I assume you mean full exposure to sunlight? That will vary with the amount of manganese and the latitude of where the bottle is sitting on the earth. I would think probaby at least a year to get some decent color. Never really saw a study done.

-Can this be done through a window pane , bottles placed in window?

yes as long as the window glass passes UV rays.

... actually Oldtimer seems to have given the answers I would have so I wont repeat them all. The answer about poor taste is one that I often point out. Some people like the dark amethyst "unnatural" looking bottles, most seem to not like them. Xrays arent used to color glass as far as I know. UV light is normally used but some bottles are also irradiated with stuff like neutron radiation from reactors. This can cause some odd bottle colors like brown coke bottles.

 

[FlouiseA27]

So is there any such thing as a true amethyst antique bottle?
Or are all the "amethyst" bottles we find the result of a clear bottle exposed to sunlight?
If there is such a thing as an actual amethyst antique bottle, is there any way to determine whether it was made that way or if it was exposed to sunlight?
This is a very pretty "Larkin" bottle I have.

 

[Graydigger]

Follow up to SCA questions. I decided to try the sun rather than UV light methods. After 4 months in a tinfoil-lined cardboard box exposed to all the sun we can get in western Oregon from April thru July, a Bonney Bros. whiskey bottle that was absolutely clear is now a good medium amethyst, and two others that were just tinted are also medium amethyst now. So 4 to 6 months of decent sun seems to do the job, as they are as colored as I want them to be. The original question stimulated a lot of discussion last year--both pro and con. Thanks for all the input.

 

[GuntherHess]

So is there any such thing as a true amethyst antique bottle?
Or are all the "amethyst" bottles we find the result of a clear bottle exposed to sunlight?
If there is such a thing as an actual amethyst antique bottle, is there any way to determine whether it was made that way or if it was exposed to sunlight?

Yes, there are true amethyst bottles that were made that way. Many early hair treatment bottles such as Mrs Allen's were amethyst. They tend to be very dark purple. Most clear bottles that turn amethyst are not that dark except for some heavily irradiated ones.

 

[NorCalBottleHunter]

heres a pair of flasks that supposedly sat on a beach in australlia for a long time before they were found, the sun really got to them. i was always told the bottle itself contained magnisum or something that when hit with U.V. rays it turned the color it does?

 

[NorCalBottleHunter]

whats that supposed to mean, lobeycat?