I pick up pebbles everywhere I go. I may have inherited this obsession from my grandparents, both geologists, whose garden was filled with beautiful stones they had gathered on expeditions. I inherited many of these stones and I’ve gathered countless others over the years. My collection piled up in buckets along the side of my house for a long time, waiting to be put to use.
Then I discovered pebble mosaic as an art form when I journeyed to Spain and Portugal. I had no idea that pavement could be so beautiful. The Plaza de España in Sevilla is carpeted in acres of river pebbles set in waves, and the sidewalks of Lisbon swirl with exquisite black-and-white patterns.
At my home in Portland, Oregon, I set about teaching myself how to make these mosaics, taking my collection of pebbles and setting them in mortar. I’ve been using essentially the same technique for many years now.
My first project was the patio in my backyard. I built it over an old pea-gravel patio, using curving forms for an undulating shape (photo at right). Since I’m interested in natural systems and universal symbols, I turned my patio into a series of mandalas, medicine wheels, dividing cells, quantum energy waves, snakes and spirals, eyes, and stone flowers. In addition to pebbles, I included colored marbles, which sparkle in sunlight and shimmer in moonlight.
The potential applications of pebble mosaic are amazingly diverse, the materials are relatively inexpensive, and the results can be spectacular. I’ve used this medium to craft stepping stones, pathways, patios, walls, steps, ponds, fountains, and edging strips for lawns.
Gather and sort the pebbles
For the process to go smoothly, I always sort pebbles in advance. If I want to create patterns using stones that are specific colors and sizes, I divide them into separate containers. Wetting rocks is the best way to see their colors and striations. Large plastic nursery pots work well for the sorting and wetting.
I buy pebbles in bulk in the form of drain rock. They are inexpensive, but it takes time to sort them. I usually do my sorting at the supply yard, throwing water on the pile so it’s easier to see the colors. In addition to sorting for color, I’m also looking for specific shapes. I select rocks with the idea that when I set them in the mortar, the surface facing up will be fairly flat.
The stones I use vary in size from about 8 inches in diameter to tiny pieces of pea gravel for filling small gaps. Marbles work well for this, too. Flat, smooth stones of any size can be used. Presorted rock can also be purchased in bags, but it’s considerably more expensive.
My favorite place to gather rocks is out in nature. For instance, gravel bars along rivers are good spots to look. In many places, rock-gathering is prohibited, so make sure it is legal to collect the rocks, and be sensitive to the impact that removing them might have.