# Glass or Ruby? **URL:** \ **Category:** Factual Questions\ **Created:** [February 5, 2006, 4:27am UTC](https://boards.straightdope.com/t/glass-or-ruby/343070 "2006-02-05T04:27:16Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [February 7, 2006, 12:56am UTC](https://boards.straightdope.com/t/glass-or-ruby/343070/21 "2006-02-07T00:56:15Z")
> [@Spectre of Pithecanthropus](#): > > Isn’t the UV component missing from a lightbulb, or significantly reduced, as compared to sunlight? Very much so. There’s almost no UV in the light output of a typical incandescent lamp. ---
**Author:** ![scotandrsn](https://avatars.discourse-cdn.com/v4/letter/s/a4c791/32.png) [@scotandrsn](https://boards.straightdope.com/u/scotandrsn)\ **Post date:** [February 7, 2006, 1:05am UTC](https://boards.straightdope.com/t/glass-or-ruby/343070/22 "2006-02-07T01:05:06Z")
> [@Otto](#): > > And here I thought this was going to be about Cinderella versus Dorothy. > > I am _so_ gay. Maybe you cut it in half, bang the two pieces together, saying “there’s no place like home”, and if you wake up in Kansas, you’re onto the real McCoy! ---
**Author:** ![Spectre\_of\_Pithecanthropus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spectre_of_pithecanthropus/32/12343_2.png) [@Spectre\_of\_Pithecanthropus](https://boards.straightdope.com/u/Spectre_of_Pithecanthropus)\ **Post date:** [February 7, 2006, 1:49am UTC](https://boards.straightdope.com/t/glass-or-ruby/343070/23 "2006-02-07T01:49:24Z")
> [@Spectre of Pithecanthropus](#): > > No, I do have the idea of rubies brightening in sunlight from a highly reputable source, the [Simon & Schuster Guide to Gems and Precious Stones](http://www.amazon.com/gp/product/0671604309/sr=1-1/qid=1139273375/ref=sr_1_1/104-9521961-3089527?%5Fencoding=UTF8). > > Isn’t the UV component missing from a lightbulb, or significantly reduced, as compared to sunlight? I have to recant, partly, because my memory of the book was somewhat inaccurate. For this particular item, Amazon lets you search the book online and I was able to find the citation. Apparently it’s any _strong_ light, not necessarily sunlight that does the trick. I still think that the stronger the UV component, though, the more noticeable the effect would be. ---
**Author:** ![Zoe](https://avatars.discourse-cdn.com/v4/letter/z/a4c791/32.png) [@Zoe](https://boards.straightdope.com/u/Zoe)\ **Post date:** [February 7, 2006, 7:43am UTC](https://boards.straightdope.com/t/glass-or-ruby/343070/24 "2006-02-07T07:43:56Z")
You guys are just incredible! I think it’s glass, but your responses have made it bearable. **crowmanyclouds** , that link was particularly helpful with the photographs. ---
**Author:** ![MelCthefirst](https://avatars.discourse-cdn.com/v4/letter/m/eada6e/32.png) [@MelCthefirst](https://boards.straightdope.com/u/MelCthefirst)\ **Post date:** [February 7, 2006, 8:00am UTC](https://boards.straightdope.com/t/glass-or-ruby/343070/25 "2006-02-07T08:00:46Z")
> [@picunurse](#): > > Garnets can range from pink to red/brown. I have a pink one. They can be green too - I have some. ---
**Author:** ![lee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lee/32/7455_2.png) [@lee](https://boards.straightdope.com/u/lee)\ **Post date:** [February 7, 2006, 2:19pm UTC](https://boards.straightdope.com/t/glass-or-ruby/343070/26 "2006-02-07T14:19:44Z")
One of the most telltale inclusions in glass is a round bubble. Little round bubbles are fairly likely in glass, but not likely in most natural stones. ---
**Author:** ![chrisk](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@chrisk](https://boards.straightdope.com/u/chrisk)\ **Post date:** [February 7, 2006, 2:24pm UTC](https://boards.straightdope.com/t/glass-or-ruby/343070/27 "2006-02-07T14:24:08Z")
> [@MelCthefirst](#): > > They can be green too - I have some. But only a **blue** garnet is worth enough to buy your freedom from the prison mines of Chthon… wait a second, that part was probably made up. 😉 [Previous page](https://boards.straightdope.com/t/glass-or-ruby/343070.md?page=1)