I have always been astonished to find that no matter how obscure a subject, it is covered in agonizing detail somewhere on the internet. People who get interested in something tend to obsessively compile data, and the internet gives us a place to store it where other people can benefit from their obsession.

But I was still surprised to find out that sea glass is a “thing.” Since childhood, I had always regarded sea glass as a delightful side benefit of walking on beaches; suddenly you come across a jewel lying on the sand. I’m not talking about broken beer bottles here, though many have started out this way, but the softly abraded and frosted fragments of well-worn sea glass.

This past winter, El Nino raged up and down the California coast, sending monster waves to dig sand off the beaches, exposing stones, flinging trees and driftwood up onto the beaches, and—exposing tons of sea glass. After a storm, my daughter Kerry went hunting for sea glass, and showed up hours later with an enormous bag of the stuff—white, clear, blue, aqua, brown, amber, and many shades of green. As she began sorting through it, she also began searching the internet for information. It turns out that people have written entire books on the subject, identifying and categorizing different kinds of sea glass by origin, color, composition, original usage, and on and on and on. There’s one man who is an expert in sea glass bottles, and he can tell you where they were made, by whom, and how they were used from pieces of glass.

Incredibly rare to find an intact scent bottle.

One of the most surprising things we discovered was “UV glass”; glass that contains uranium, resulting in a yellowy-green, light-catching material called “Vaseline glass.” (Not because it was used as containers for Vaseline, but because the glass has a greenish, somewhat oily look.) Under a black light, UV glass glows a brilliant and spooky green. One of the more unusual pieces my daughter found was a glass rod used in making millefiori jewelry that had a star-shaped central core made of UV glass. They stopped using uranium in glass around WWII, presumably because the element was needed for nuclear arms. Everything I’ve read about it indicates that there’s not enough uranium in UV glass to be dangerous, but I don’t think I’ll make any jewelry out of it, just the same.

UV, or “Vaseline” glass with uranium.

So it turns out that collecting sea glass is a huge thing where I live. The sea glass in-crowd knows the best beaches, the best times of day, the best times of the year, the best weather, the best searching techniques. My daughter encountered another woman just before daylight on the beach, holding a flashlight on a stick to catch the reflection from the glass before the sun came up. Serious sea glassers wear wet suits and use sand crab rakes, normally used to dredge up these little crustaceans for bait, to dig up the glass in the wave zone. This can be a dangerous endeavor on the Northern California coast, which is prone to riptides and sneaker waves. This past winter, a man died at Davenport Beach, his favorite sea glass spot.

Davenport is where the hard-core crowd goes. It’s a public beach, but there is a certain cadre of sea glass seekers that act like it’s Westside Story and they’re the Sharks. I will call them Glassholes. On my first visit, I saw a man digging a large hole on the beach. I wandered over and picked up a quartz pebble he had unearthed—obviously nothing he was interested in.

“I didn’t dig that up for you,” he said. So charming.

“I didn’t imagine that you did,” I said.

“Go find your own hole!”

“It’s a public beach,” I pointed out, whereupon he roared, “Fuck you!” Such a gentleman.

Another lovely Glasshole wrote a manifesto and published it on Facebook instructing amateur “toe-dippers” to stay out of the way of the real people, stay out of the water, and a bunch of other things that I don’t think have been officially sanctioned by the California Coastal Commission.

So why are the Glassholes so hostile and aggressive? Apparently, the tiny town of Davenport (it has like, three streets) was once home to an art glass factory, which threw all  its rejects into the ocean. So it is possible to find stunning pieces of multicolored glass, rare colors and shapes in the Davenport waves. Many of the sea glassers turn these pieces into jewelry, sun-catchers, and other crafty things to sell. Does this excuse  Glassholery? By no means, but I don’t think they care what I think. (By the way, there are also some lovely and generous people who hunt for sea glass as Davenport, and I do not mean to include them in the Glasshole category.) [Post-publication note: Kerry says the glass studio is still there. The glass reached the ocean due to a flood that swept three dumpsters’ worth of art glass rejects into the sea.]

I won’t be returning to Davenport, though it has nothing to do with the Glassholes. In winter, which is the best season to find glass, so much sand has been scoured away from the beach that getting to the water requires descending a 12-foot sandstone cliff. Then, of course, you have to climb up the cliff to get out. I did it, but I’d rather not these days. I am not the agile creature I used to be. (Stop that sniggering, family!)

Sea glass millefiori rod with UV star.

It’s fun finding a special piece like a marble. The reason there are sea glass marbles is not because children play marbles at the beach, it’s because ships used barrels of marbles as ballast, jettisoning the marbles as necessary into the ocean. I have heard of people who have found thousands of them—I have found four.

Sea marble.

When looking for sea glass, I can walk for miles without noticing that I am exercising. And it’s fun to go through the day’s catch with a black light to see if it will spark that spooky green glow, like the fuel rod in the intro to “The Simpsons.” I love the feeling of triumph when I find a rare color or a particularly well-worn and perfect piece. I used to hunt for shells, but I have actually found more sea glass than whole shells on these shores. Apparently, once a shell is abandoned by its owner, the rocks just beat the shit out of it. Finding an unbroken shell of any species is cause for rejoicing.

This bottle bottom says “FORBID.”

At some point, when I get my jewelry workshop set up again, I will try setting my better pieces. But I will never be the avid collector my daughter has become. Many a weekend, when I am still fast asleep, Kerry is down at the beach, looking for glass. I’d rather have breakfast, so I guess I am not a true fanatic.

Photography by Kerry Keenan Gil