The West Virginia Swirls Identification page has this type as well as another type listed as "Solids" and rarer...(picture reference included below) However, this is not an opaque solid but translucent. This one here is a sister marble to the "Triple threat" listed earlier. Glass is darker, has a "C" Swirl and snow frit inside that can be mistaken for Aventurine which is what I think occurred with the first one Both are UV reactive and the inner swirls turn Bright green under UV. I put a bright light on them both for comparison so you can see in the last picture here. This one has no missing glass, just a small bruise and a sparkle crescent