Brrown Brick?

[Berryb]

Hi; I'm new to this site. Been collectin' marbles (among other things) for nearly 30 years. 

I just got this one as part of a trade a couple of days ago. It's pretty beat up but I couldn't resist. It seems to be an odd ball. It's chocolate brown not ox and it has what could be a pontil.  It's 11/16ths.

The first pic is with another brick for color contrast and then 2 other views. Any ideas? Thanks

Bruce

 

[wvrons]

Looks like a remelt. A brick that has been reheated, maybe trying to repair. But a poor job. It is a new pontil where the marble was a stuck to a rod for reheating. The color darkened with reheating the glass.  Never heard of a brown brick. 

[Berryb]

Hadn't  thought of that. It could explain the orange peel surface and the blowouts.  But it brings up other questions about glass chemistry; why does it turn brown with a torch and not when it's a liquid during manufacture? Why did the white stay white? If cracked open would the center still be Ox colored?

I put in a sharper photo. One of the blowouts is at 3 o'clock, another just like it is opposite and just out of view. another pin hole blowout is dead center. What may be a pontil is about 7o'clock. Thanks

Bruce

[wvrons]

Good questions. I think if you break the marble open, it will all be this same main color. I am definitely no glass chemist. Just what I have experienced during many hours days years at the Jabo marble factory. It is all temperature and time. To high of temperature and the glass with different colors will turn brown and long enough will go very dark. The longer the temperature is to high the darker the brown goes. Add different colors of glass to a white or clear base glass, to many colors to fast and it will all go brown. White seems to be the last to go brown. Nice opaque white glass can be heated high enough and long enough that it will turn clear. The blow outs pinholes rough surface is a sign of reheating. Heated to high or to fast or to long will cause the gas pockets and blow outs. As you can see most white has thinned out and beginning to disappear. A little more time at this heat and the white would be gone and the color even darker brown.  The glass in the main furnace or tank can turn brown during machine made marble production. I have seen it happen several times. I have also seen opaque white glass in the main furnace turn clear. Plus not all glass is the same. Many different kinds of glass and each one can react different. I have seen a certain clear looking cullet turn ruby red when reheated properly. With the correct combinations, good results happen. But with wrong combinations, glass, heat and time, bad things happen.