Nonetheless, I wasn't entirely unfamiliar with seashells. In the living room of my grandparents' brick farmhouse, a large conch shell rose from the mahogany end table. When I wasn't much taller than that coffee table, my grandmother held the shell to my ear. The conch felt cool against my cheek. And when Grandma asked if I could hear the ocean, I nodded, mesmerized by the magical song of the sea. I fell instantly and irretrievably in love.

So I began collecting seashells, captivated by their graceful whorls, their glassy pinks, porcelain whites, and sandy browns. That's why, on a recent holiday in the south of Spain, I was dismayed to find a sparse smattering of shells--and mostly pedestrian sorts, at that--scattered on the Marbella beach. This stretch of La Costa del Sol was more given to pebbles, with the occasional clutch of purple tinged mussels and a few other relatively mundane bivalves coughed up by the unimaginably blue Mediterranean.

And then it somehow dawned on me: sea glass! Something shifted, and I decided to seek, instead of shells, those beautiful bits etched by the ocean's water, salt, and sand. Never mind that I'd never actually found any sea glass. I made my way up the beach toward a round stone tower, a vestige of a Moorish coastal lookout. I was on the lookout for sea glass, and--lo and behold--I found it. First a small piece, satiny to the touch and green as emerald. I rinsed the sea glass in a wave, and the water set the pseudo jewel sparkling.

I was hooked. The next bit was amber, followed by a chunk of milky white glass. Other pieces were a soft and delicate blue, aquamarine like the sea itself.

Over the course of the 10 days I spent on those Spanish sands, I collected literally hundreds of pieces of sea glass. My favorite part of the day involved just putting one foot in front of the other, eyes cast down, searching for that green or golden glimmer, that wink off a wet piece of clear glass rendered cloudy.

Yet how did the glass get from there to here? And what was the story of each piece? Had a ship run aground in a storm? Its supply of wine dashed upon the barnacled rocks? Had a fisherman capriciously tossed an empty bottle of beer overboard? Was this piece with the wire netting once part of a porthole? And that unusually thick green piece--could it have been a glass buoy? How many breakers had carried each piece on its journey? How many years had each bit tossed about in the roiling sea? How many grains of sand buffed the glass from transparent to translucent?

To everything, more or less, we assign value. The currency of beachcombers consists of seashells and sea glass, driftwood, smooth stones. What is rubbish to some represents treasure to others--those of us who walk with our vision focused on the sand. The creative power of the sea can turn even commonplace junk into something lovely.

I purchased luminous Majorcan pearls in Spain, but I treasure them less than my bowl of sea glass: my reminders of the sea's persuasive power to soften even our sharpest edges.