My Coin Storage

Jbuck, I think you have it!

Just like in the coin hobby, there is concern about altering the glass. It not only can be done with paint (inexpensive at Walmart), but there are those who, like toning coins with heat, will alter insulators with heat or gamma radiation.

A California company made insulators in yellow glass. Over the next 100 years+, sunlight turned them purple b/c of Manganese in the glass. Hence yellow ones are extremely rare as the verified ones are from indoor use inside factories, etc where sunlight could not hit them.

Then someone found out heating the purple ones to high temps will revert the glass to the initial yellow they were made in.

So are they altered? Well... the debate goes on.

A lot of irradiated (gamma rays) glass will turn purple (as the bottle hobby knows so well). And this command a higher price b/c people like the prettier colors more.

Irradiation was an area of the hobby I researched for educating on altered pieces so eBay-wanna-be-rich-with-fakes sellers don't make so much money from the unsuspecting.

Thankfully, after 15 years or so, and hundreds of altered glass insulators later, I have seen only one I was not sure of. Irradiation does not normally produce a true color when compared with known, unaltered pieces.

Also, irradiated glass almost always reverts to their original color (or close) when exposed to direct sunlight for awhile.


So if you ever see a pretty, purple glass insulator for sale that is specifically a grape lollipop purple - forget it. You are being taken by a fake.

There are plenty of legit shades of purple, but grape Kool-Aid or grape lollipop is not one of them. And your grapey, pretty, historical telegraph gem sitting in the sun will likely start to revert to aqua very quickly.

I simply mention this b/c it is the most common faked color.

Oh... painted ones - easy to tell - scrape the surface - the paint comes off.

You are very welcome - actually did some seminars on this topics!