Alan

A small fraction of mine:

The bag is not right and appears to be new.

1st: Akro

New MK.

Hopefully Covid will ease and we can get back to shows. Ebay and Facebook are poor sisters compared to in-person shows.

I have never downsized - or frankly, even sold anything in the past 20+ years. But I think its helpful to step back ask ourselves what we are doing this for. What is the focus of the collection? If there isn't a focus - then its more of an "accumulation" than a collection. Our focus may shift over time - and some re-thinking may be in order. FWIW: A well known person who has been in the hobby for 35+ years once said: If you don't have it on display - its time to let it go.

That assumes that factories sourced their sand from single sources which were in themselves consistent. I wouldn't assume that. In glassmaking, bubbles are usually a phase in cullet/substrate melting. Glass which is not fully up to temperature can often contain bubbles. I saw that in a glass pot on Wednesday.

Glass flow looks Master.

All pics are out-of-focus, but doesn't appear to be a furnace.

Nothing rare about those colors. In fact I think they look rather muddied/muddled. Someone overpaid by a large margin.

What appears to be an oily surface is the first thing I noticed.

It has a slight flat spot. On Facebook it would probably be described as: "Mint surfaces with a small "as-made" tool touch mark, as seen under 10x magnification". 😜 This came from the factory site. It was with an Akro machine funnel. I got in in a free box of misc. weird dug items.

From the second photo we can see fine wear across the glass surface without much in the way of impact hits. That suggests that it wore for some time against something abrasive - probably other marbles, or it was lost in the dirt over many freeze-thaw cycles, and then later found.

Opinion: Its only worth $50 if there are two twenty dollar bills under those marbles.

It looks contemporary in those pics - but the color saturation looks way too artificial to represent real glass. What did you do make it so? HDR and a light box?

Nothing wrong with a 5MP camera. A well-focused and lit 5MP pic is far, far better than a fuzzy, out-of-focus pic at 3 times the resolution.

Those pics are almost all out of focus - but it doesn't appear so. Center select your focal point and back your camera away until you are within the lens focal length.

Corning Glass studio made a Thanksgiving dinner made of 100% glass! If you haven't visited the Corning Glass Museum - you are missing a significant experience.

The bottom left doesn't look like wear. It looks like multiple impacts. I'd say "walk away". "Don't sell a marble to yourself".

Is that some plastic film adhering to the Onion - or has it taken a good beating?

Its missing the wispy white that would make it a Popeye. Plus as noted before, its not a corkscrew.