I am not an expert on ancient glass, but I've bought and watched enough fakes to see the bulk of what is and is not. 

I did not realize at first that, irridescence proves nothing. I have some glass that was dug up in Germany and in the states, from within closed glass factories, dug-up in the remaining grounds, artifacts,  that displays the best irridescence you could want. Except this glass is less than 100 years old.. Yes it grows on glass in a little as 50 years..

The other thing most do not realize is that, ancient glass techniques are primitive..  What does this mean? There are so-called experts who sell this stuff telling you about lost techniques, it is a bunch of garbage. Primitive techniques are simple, in fact, most glass blowers learn primitive glass blowing equal to or better than what is dug-up..  Primitive means, it is easy, simple to recreate, I.E. primitive,  A child creating art in grade school is primitive..

One of the worse crimes at e-bay currently, yes crimes, is the sale of so-called; Phoenician or paste glass assembly products. "ancient eye beads" "Ancient amphora" "core formed" another so-called-expert saying in their auction about, this being a lost practice. It is not, and if any real genuine core formed, or Phoenician, artifacts have been sold on e-bay it's rare! extremely rare!  What I am saying is, people are buying fakes!! There are hundreds-thousands of these fakes being offered monthly. A few excelent articals I've bought are made convincing well, except! The con artists used metal flake paint as irridescence, and paint as a thick white paste to emulate ancient growth..  In real life, These types of relics easily sell in the thousands of dollars range.. Not for $50-100-300 as is commonly sold on E-bay.

The old adage, 'if it's to good to be true? It is!!  I love shopping at e-bay and threw my almost 11 years of buying at e-bay I've run across some incredible findings, sure there are great things to be found, but I have a hard time just watching people get ripped off by con-artists. Which is why I am attempting to warn you, others. luckily I got my money back from the con-artists who sold me the fakes i've bought, while I've watched several others buying from the same person, Fakes.. E-bay will do nothing to help you unless you can find a real live expert who will tell e-bay about each and every fake sold. it's a near impossible task, that e-bay could not afford to do.

These fakes are offered by every so-called "expert" on e-bay, I've seen almost every single ancient seller offer them. Including one who claims to be an e-bay antiquities expert..  Dont be fooled by these people, you can not get antiquities on e-bay except very rarely for a bargain. Your competition, 'other collectors' are watching too, and if you think they would not drop a grand on a real peice in a heart beat, you are only fooling yourself.. Beware, check with real antiquities experts before you spend your hard earned cash on fakes.. Read sellers warranties, like, "refund given if you have a state experts testimony!" This is a joke!! Most people can't find a expert in antiquities, and these sellers know this..

Learn about glass. Understand that glass is glass, there's no difference between glass made 4,000 years ago and today! it is made of the exact same chemicals, ingredients used for the past 4,000 years.. That is to say, the fakes are made with the exact same "primitive" materials, ingredients, used way back then.. It is so simple, any glass blower can use sand and silica and create a relic. Or what might appear to be ancient very well could have been made only 100 years ago.. Think about it, before you toss your money out the window on fakes.. Beware, most sellers list their auctions with privet bidders because they do not want others to warn you about the fakes they have bought..