Alan

Handmades:

Some handmades: Solid cores:

A huge chunk of Akro cullet:

Ro Purser:

A specific combination of TWO colors is pretty specialized and may make for a quiet thread for a month - kind of like the "gold" thread.

They look to me like patches from a beginning or end of run that are missing a second major color component. Personally I wouldn't give them a seperate name as if they were a discrete production item....they appear to have been discarded because one glass color pot wasn't flowing.

More gold and metallic that I forgot that I had: Lundberg: Hamon:

True gold will be hard to find (IMO). Here is some silver metallic: Josh Simpson:

Mark Matthews:

Your understanding is correct.

Deep red glass was originaly formulated with gold dissolved in an acid. The same was true (IIRC) for pink - just at a lesser amount of gold. Not all reds required the use of gold. I think that the use of gold was discontinued in the 1930s or 40s by using selenium - and later a copper formula... both which were cheaper. U.S. marble manufacturers would have been restricted from using gold during WWII.

Agree with Mike above - pink glass formulas were expensive (and marbles were cheap). Galen's point is also a good one.

Richard Clark makes some very appealing designs. Here is some of his work that I own:

They are micas - made by Bill Murray.

Lundberg Studios Van Gogh Sunset: Lundberg Studios Sea Crest: Lundberg Studios Starry Night: Bill Murray: Bill Murray (purple outer bands and purple dichro on green solid core):

There is no way of knowing the answer to that supposition. If I had to guess - based on the shape of the rollers, the fact that they are smooth and constantly in motion (unlikely to hold metal salts well) - if it were a one-time occurence - probably fewer than 12. If it happened 3-5 times over a year - then 3-5 times that. Then divide by the high percentage that were lost to time and/or discarded and never dug from a dump site. It is really a freak/chance occurence - essentially an unintended and unwanted contamination of a marble whose production design isn't supposed to look like that. Manufacturers were pretty good at culling their production pieces and dumping the rejects.

If your aventurine is strictly at the surface like mine - then my guess of glass colorant salts on the rollers and some hot marbles picking it up seem all the more likely. Otherwise there would be some in the green or clear matrix. Thanks for the pic.

If you have an example I'd be interested in a photo or two. I've been thinking about the unusual surface layer of "aventurine" and why it would be that thick, right on the surface, that color etc. and how that would occur in the glass pot. That led me to a (completely factually unsupported) guess that the machine operator may have been feeding colorant (metal salts) into the pot by shovel (standard method) and could have dropped some on the rollers. When the next few marbles went through the rollers - they would have picked up the loose dry powder - which was then fused to the glass (but only on the surface). This color of "aventurine" isn't the normal color we see in subsurface glass and is far too dense....hard to imagine any other reason it would be on the surface only. Anyway...thats my unsupported speculation.

Thought I would share this Akro Sparkler with a little more than half of the surface covered with a dense emerald green aventurine:

In West Virginia.

That would put it at 1958.