I have been beach combing since I was a little kid... and picking up sea glass for just about as long.
The most "treasured" pieces I find-- the ones most likely to elicit an "oooh" and "aaaah" response-- are those round fat gumdrop-like pieces that show up only once in a great while.
They are fairly rare because they-- by definition-- have to come from a pretty thick piece of glass. And most glass isn't particularly thick.
If you think about it, the vast majority of glass we see comes either from common bottles or jars, or from glass tableware. And this glass is seldom more than a quarter inch (about 6mm) thick... maybe a few bottoms and edges get up to 3/8" (9mm) thick.
A fat round piece like the one pictured above-- 1 1/4" (30mm) long by almost 3/4" (19mm) thick can come only from a very limited number of origins.
Few pieces do, which is perhaps a large part of the appeal of these "round bubbles," at least to me.
So where does a piece of sea glass like the one in the top photo come from? My best guess is that this was part of an old glass insulator, probably the top part. I remember seeing them in many shades of blue and green, when I was a kid, and I have since seen them as "collectibles" at flea markets. Since they are no longer in functional use, the chances of more sea glass like this being created is near zero.
- 1960 vintage Danish national now living in the Pacific Northwest... active in the global HSP community; active beach comber and sea glass collector; lifetime collector of postage stamps from Scandinavia; writer and consultant, primarily to the metaphysics and self-help industries, writer at OM Times magazine; artist who doodles on rocks; eBay & Etsy entrepreneur and studio and production assistant at Radio Nahmaste.Diverse enough for you?