# What's the difference between "crystal" and "glass"? **URL:** \ **Category:** Factual Questions\ **Created:** [September 15, 2012, 5:19am UTC](https://boards.straightdope.com/t/whats-the-difference-between-crystal-and-glass/634771 "2012-09-15T05:19:04Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![FoundWaldo](https://avatars.discourse-cdn.com/v4/letter/f/dfb087/32.png) [@FoundWaldo](https://boards.straightdope.com/u/FoundWaldo)\ **Post date:** [September 15, 2012, 5:19am UTC](https://boards.straightdope.com/t/whats-the-difference-between-crystal-and-glass/634771/1 "2012-09-15T05:19:04Z")
I have quite a bit of expensive “crystal.” Waterford (wedding gift), Riedel, Schott Zwiesel, etc. They’re nice, and I like them. But really, as far as I can tell, they’re just fancy glasses. Is there really some technical difference between “crystal” and “glass” or is “crystal” just a synonym for “expensive glass”? ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [September 15, 2012, 5:27am UTC](https://boards.straightdope.com/t/whats-the-difference-between-crystal-and-glass/634771/2 "2012-09-15T05:27:31Z")
Crystal is a type of glass. Other glass contains calcium, but crystal contains lead. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [September 15, 2012, 5:34am UTC](https://boards.straightdope.com/t/whats-the-difference-between-crystal-and-glass/634771/3 "2012-09-15T05:34:54Z")
The price. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [September 15, 2012, 7:43am UTC](https://boards.straightdope.com/t/whats-the-difference-between-crystal-and-glass/634771/4 "2012-09-15T07:43:11Z")
> [@TriPolar](#): > > The price. No, it really is about the metal oxide content. Lead oxide makes crystal heavier and more sparkly than ordinary glass. These days lead oxide is often replace by others, eg barium or zinc, but glass labelled as lead crystal is still the real deal. > **[Lead glass](https://en.wikipedia.org/wiki/Lead_glass)** > > Lead glass, commonly called crystal, is a variety of glass in which lead replaces the calcium content of a typical potash glass. Lead glass contains typically 18–40% (by mass) lead(II) oxide (PbO), while modern lead crystal, historically also known as flint glass due to the original silica source, contains a minimum of 24% PbO. Lead glass is often desirable for a variety of uses due to its clarity. In marketing terms it is often called crystal glass. > The term lead crystal is, technically, not... ---
**Author:** ![california\_jobcase](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@california\_jobcase](https://boards.straightdope.com/u/california_jobcase)\ **Post date:** [September 15, 2012, 1:12pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-crystal-and-glass/634771/5 "2012-09-15T13:12:21Z")
Glass is not crystalline. Glass is an amorphous solid without a crystal structure. Lead crystal is called crystal because of its appearance, as noted in the posted Wikipedia link. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [September 15, 2012, 2:41pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-crystal-and-glass/634771/6 "2012-09-15T14:41:07Z")
> [@Colophon](#): > > No, it really is about the metal oxide content. Lead oxide makes crystal heavier and more sparkly than ordinary glass. My mother has a _lot_ of crystal, mostly Eastern/Central European. There is an obvious difference between crystal and glass. As you said, crystal is heavier and has a sparkle to it glass doesn’t have. I personally don’t care and wouldn’t pay for pretty vessels myself, but it’s not just a matter of price. ---
**Author:** ![Lasciel](https://avatars.discourse-cdn.com/v4/letter/l/e79b87/32.png) [@Lasciel](https://boards.straightdope.com/u/Lasciel)\ **Post date:** [September 15, 2012, 3:30pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-crystal-and-glass/634771/7 "2012-09-15T15:30:22Z")
Related question - for lead crystal, are you screwed if you drink from it regularly (daily, weekly, monthly? My inlaws have a lovely set of drinking glasses from Holland which are lead crystal, and are starting to hint about the various kids choosing what they want to inherit… ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [September 15, 2012, 5:18pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-crystal-and-glass/634771/8 "2012-09-15T17:18:27Z")
> [@Lasciel](#): > > Related question - for lead crystal, are you screwed if you drink from it regularly (daily, weekly, monthly?) [The assembled knowledge of Wikipedia](http://en.wikipedia.org/wiki/Lead_glass#Safety) seems to be that you should not store liquids or food in lead crystal; the longer a liquid is in contact with the lead crystal, the more lead will leach out of the class into the beverage. However, pouring some wine into a crystal wine glass and drinking it with dinner doesn’t add enough to your lead intake to be worried about. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [September 16, 2012, 3:43am UTC](https://boards.straightdope.com/t/whats-the-difference-between-crystal-and-glass/634771/9 "2012-09-16T03:43:59Z")
> [@california\_jobcase](#): > > Glass is not crystalline. Glass is an amorphous solid without a crystal structure. Lead crystal is called crystal because of its appearance, as noted in the posted Wikipedia link. Confusingly, I think lead crystal isn’t crystalline either, is it? Unlike eg sapphire, diamond or even quartz. ---
**Author:** ![california\_jobcase](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@california\_jobcase](https://boards.straightdope.com/u/california_jobcase)\ **Post date:** [September 16, 2012, 5:36pm UTC](https://boards.straightdope.com/t/whats-the-difference-between-crystal-and-glass/634771/10 "2012-09-16T17:36:24Z")
Lead crystal is glass, hence not a crystal. It just looks like quartz crystals. ---
**Author:** ![the\_diego](https://avatars.discourse-cdn.com/v4/letter/t/7bcc69/32.png) [@the\_diego](https://boards.straightdope.com/u/the_diego)\ **Post date:** [September 17, 2012, 3:57am UTC](https://boards.straightdope.com/t/whats-the-difference-between-crystal-and-glass/634771/11 "2012-09-17T03:57:25Z")
Just some term-straightening: a crystal has to have a definite atomic/molecular structure that can be cumulated megascopically (therefore have a crystal structure.) But not all crystals found in nature are perfect of course, they are often shapeless lumps but their molecular structure is consistent. That’s how you define it. Glass is just a jumble of SiO2 molecules with some mixturesand impurities like lead oxide. You can cut and facet your glass into a nice brilliant cut diamond shape, in which case you had made it “crystalline” in shape. But it’s still not a crystal.