Abalone Shell Mexico

A five to six inch abalone shell, sold as a working bowl. The shell is built in two layers, an outer one of prismatic calcite and the nacre inside, and the nacre gets its toughness from how it is stacked: microscopic tablets set in an organic mortar, which is the arrangement materials scientists keep trying to copy. The rim is still the thin part. Handle it by the body, not the edge.

It is a sea snail. The line of small holes near one edge is where the animal vented water off its gills, along with waste and spawn. Four to ten are open at a time; the rest are sealed behind as the shell grows forward.

The color is structural, not pigment. The inside of the shell is nacre, built from microscopic aragonite platelets stacked in layers roughly the thickness of a wavelength of light, so the light bouncing off successive layers interferes with itself and comes back split into color. Tilt it and the colors move, because the angle changed. That is also why a burn mark is permanent: heat wrecks the stack.

Good to Know

5 to 6 inches. Sizes, colors and shapes vary; every one is a different animal. Put a layer of sand in the bottom before you burn anything in it. The shell is calcium carbonate and it will scorch, and once the nacre has taken heat the color is gone from that patch for good. Sand takes the heat instead and it also lets you stub a stick out cleanly. Rinse and dry it if it gets ashy. Keep it off a hot sunny sill too, not because the color fades (structural color has no pigment to fade) but because sustained heat dries the nacre out and cracks it.

Try It With

A white sage bundle, palo santo, or red cedarwood flakes if you prefer loose material over a stick. A soapstone smudge bowl is the heatproof alternative that will never scorch. More in burnables.