Glass (categorising)

[sculduggery]

Me and my colleagues are in disagreement over a question that appears on a paper. The question is-To which category does glass belong? A) Natural B)Metals C)Ceramics or D) Plastics. Although I am aware that Sand and Silica are natural products and glass can be created when lightening strikes. I dont think glass is a natural as I dont think there is a natural category as such.I think it is a ceramic, Please could you tell me if I am correct or am way off the mark as usual.

Thanks in anticipation,

[Panthera Leo]

Hello sculduggery & welcome to PF

If I was to choose from those categories, My choice would be Ceramics too.

It's true that there are a huge number of naturaly occurring Glasses but I wouldn't place glass under naturals because it's not neccessarily natural all the time :) But its always a ceramic if I my knowledge is correct. A very famous and pricy naturaly occurring glass is Opal (the gemstone) because its an amorphous SiO2 with high water content (5-10%).

Best Wishes

[sculduggery]

Thanks Panthera.

I have posted this on several forums and this is the only reply I have had, Sounds like a good answer too, Thanks again.

Robert

[MalliCk]

yeah glass is categorized as ceramic material, and yes ceramics also do occur naturally; look for Obsidian, a naturally occuring glass in volcanic eruptions.
but nevertheless its always a ceramic.

[sculduggery]

yeah glass is categorized as ceramic material, and yes ceramics also do occur naturally; look for Obsidian, a naturally occuring glass in volcanic eruptions.
but nevertheless its always a ceramic.

Thank you Mallick