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Posted by Jenna Mast  
March 29, 2012 03:15AM
I came across this add on craigslist for "EXTREMELY RARE Museum Size Fluorescent Minerals & Crystals" but they look awfully similar to alum crystals to me.

Re: Alum?
March 29, 2012 09:02AM
Ceratinly artificial xls. Some of them may be synthetic "Alum" xls, some may be synthetic Cu sulphate (Chalcanthite) xls, some may be potassium chromate xls (which, by the way, is toxic). But all are lab-grown and artificial.

avatar Re: Alum?
March 29, 2012 03:07PM
All are definitely lab-grown. That they were once owned by a famous Beverly Hills type is irrelevant.

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