Rob Ellis sets out in the muted late-afternoon sun, searching for glass for it to shine through. He plucks a clear piece from the tide line, then tosses it back because of its sharp edges. “Too young,” he says, as if it’s a small fish.


He’s looking for glass that’s been well tumbled by the ocean, giving it a frosty, lightly pitted appearance. A broken bottle top with soft, worn edges makes it into Ellis’ fanny-pack stash of keepers. “This is different,” he says. “This is interesting.” 


He makes a beeline for a cornflower-blue shard. “Oh, that!” he exclaims gleefully. “You can find that during the week. On the weekend, everybody’s combed it over.”


Ellis is one of a cadre of local sea-glass collectors who comb Monterey County’s beaches, looking for the treasure in other men’s trash. He says a typical Saturday at low tide brings about a half-dozen sea-glass pros to this beach, identifiable by their wetsuits and mesh scoops, while another couple dozen hobbyists pick along the shoreline in street clothes. 


His precocious 9-year-old daughter, Devin, is along for the hunt. She explains that the most common sea glass colors are clear, brown and green, in that order. Her favorite, blue, is less common; red and purple are the rarest.


Ellis, a Pacific Grove-based photographer, has been collecting sea glass since he quit a 20-year career as a computer programmer. “It just wasn’t me,” he says. “I love being outdoors.”


Members of the California Sea Glass Association know the feeling.


“What is it about a piece of worn surf-tumbled glass that is so alluring? Is it the hunt? Is it the surprise treasure of an emerald green gem washed up after a high-tide?” Santa Cruz Sea Glass owner Krista Hammond writes on the CSGA website. “It was the colors I was drawn to, the fact some pieces so closely resembled raw gems as the sun illuminated them on the wet sand.”


Collectors use the glass in all manner of artsy creations, particularly jewelry. “It’s unique, because it’s beautiful and translucent,” says Brigga Mosca of the Gallery at Ventana in Big Sur, which sells silver-set sea glass collected between Santa Cruz and Big Sur. “Even though it’s man-made, it’s taken a turn at being altered by nature.”


Ellis has been taking jewelry classes at Monterey Peninsula College for the past three years. He works his favorite glass pieces into earrings and pendants, and sells them at the annual Santa Cruz Sea Glass Festival, happening the first weekend in November this year at Cocoanut Grove. Ellis and his sea-glass mentor, Margaret Huffman of Pacific Sea Glass Designs, are also planning a Monterey sea glass festival for summer 2013.


Choice collecting spots, Ellis says, include Del Monte Beach, Seaside State Beach and the Pacific Grove coast near Hopkins Marine Station. The abundance of sea glass on these shores might have something to do with the way people used to dispose of their trash. 


Jeff Lindenthal, spokesman for Monterey Regional Waste Management District, says at the turn of the century, residents steered their horse-drawn carts loaded with garbage to Lovers Point in P.G. and dumped the contents into the ocean. In 1920, the cities of Monterey, Seaside, Carmel and P.G. established a public dump on the site of a former sand mine in what is now Sand City. For the next 30 years people dumped their garbage on the bluff by day and burned it at night, leaving ash and residues including broken glass. 


Ellis says the result was a telltale multicolored, fused-together glass: “It ends up looking crazy.”


There are infinite other sources for the shards of glass that make their way to the sea. Lindenthal speculates old U.S. Army operations may have deposited glass in the Marina Dunes area.


The mystery of the history, after all, is part of the sea glass allure.


Reaching the southern edge of Sand City’s beach, Ellis wades chest-deep into the waves. He feels with his toes for coarse gravel, then scoops, pulling up a catch of rocks, wriggling sand crabs and a few choice nuggets of sea glass. He picks out one with an air bubble and another, rare pink, and tucks them into his pack. The he wades in for a second scoop, then a third and a fourth. 


“Alright, one more,” he says. Devin rolls her eyes.


“This is a hobby for the obsessive-compulsive,” Ellis says with a laugh. “It’s hard to stop. It’s always the next one that’s gonna be really cool.” 


Learn more about the art of sea glass at www.californiaseaglassassociation.org