# old bottles **URL:** \ **Category:** Factual Questions\ **Created:** [January 18, 2005, 9:05pm UTC](https://boards.straightdope.com/t/old-bottles/285423 "2005-01-18T21:05:29Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![ekim1969](https://avatars.discourse-cdn.com/v4/letter/e/8797f3/32.png) [@ekim1969](https://boards.straightdope.com/u/ekim1969)\ **Post date:** [January 18, 2005, 9:05pm UTC](https://boards.straightdope.com/t/old-bottles/285423/1 "2005-01-18T21:05:29Z")
How many different bottling companies was there in Forest City Pa. And why do some of them turn purple in color. ---
**Author:** ![zut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zut/32/2875_2.png) [@zut](https://boards.straightdope.com/u/zut)\ **Post date:** [January 18, 2005, 9:26pm UTC](https://boards.straightdope.com/t/old-bottles/285423/2 "2005-01-18T21:26:17Z")
Welcome the Straight Dope, **ekim1969**. Does this question relate to one of **Cecil** ’s columns? If so, it would be useful to indicate which one it is – it’s difficult to determine from context which column you’re referring to. If it’s a question unrelated to any of **Cecil** ’s columns, you might want to ask a moderator to move this thread to [the General Questions forum](http://boards.straightdope.com/sdmb/forumdisplay.php?f=3) – there’s more likelyhood of receiving an answer there, I think. In any case, welcome aboard. ---
**Author:** ![MaryEFoo](https://avatars.discourse-cdn.com/v4/letter/m/ba8739/32.png) [@MaryEFoo](https://boards.straightdope.com/u/MaryEFoo)\ **Post date:** [January 20, 2005, 6:05am UTC](https://boards.straightdope.com/t/old-bottles/285423/3 "2005-01-20T06:05:00Z")
My father told me old bottles slowly turn purple due to the effect of sunlight on the glass, and that bottles found in the Nevada desert turned color faster than bottles that received less sun. Can’t help you with the number of bottle factories. ---
**Author:** ![hammerbach](https://avatars.discourse-cdn.com/v4/letter/h/73ab20/32.png) [@hammerbach](https://boards.straightdope.com/u/hammerbach)\ **Post date:** [January 20, 2005, 6:22am UTC](https://boards.straightdope.com/t/old-bottles/285423/4 "2005-01-20T06:22:19Z")
The color change is due to the UV in sunlight causing an oxidation of manganese in the glass. [Here’s a FAQ about shotglasses,](http://www.pre-pro.com/faqs.htm) chosen mostly at random, to start you off. More can be found by googling terms like glass, sunlight, manganese, purple… ---
**Author:** ![Ol\_Gaffer](https://avatars.discourse-cdn.com/v4/letter/o/8e8cbc/32.png) [@Ol\_Gaffer](https://boards.straightdope.com/u/Ol_Gaffer)\ **Post date:** [January 20, 2005, 7:20pm UTC](https://boards.straightdope.com/t/old-bottles/285423/5 "2005-01-20T19:20:22Z")
Can’t help you on the bottling factories either. But…we (as in the U.S.) imported most of our manganese from Germany back in the day. With the outbreak of WWI, the manganese supply dropped significantly and was eventually removed from the glass composition. Therefore, amethyst bottles generally date to pre-WWI.