Sea urchins are one of my top 3 favorite specimens to collect.
They are abundant, easy to spy, and if you are on a good sea urchin beach, you are probably surrounded by rugged, salty, isolated and pristine shoreline--the best kind if you ask me!
When Atlantic Green sea urchins are alive, they are an inky purplish greenish colour and covered in sharp needle-y spines that move all around like curious--but dangerous--feelers. Unless you are collecting them for food, just walk away and let these ones be. There are plenty of empty ones, washed ashore by the changing tide, devoured by gulls and crabs, etc. With time on the shore, they drop their "needles" and get sun-bleached, becoming white polka-dotted pale green "eggs"--fragile but: coat them with watered down white glue to strengthen them enough to use in your projects.
Urchins, like starfish and sand dollars, have RADIAL symmetry--meaning they can be divided into 5 identical pieces if you were to break them apart from the middle outward, like a sliced pie.
My FINDERS KEEPS urchin earrings came about when I accidentally discovered how neatly a dropped shell split itself apart, and how neatly jagged the edges were. I quickly set to work rounding out the tops and bottoms of the wedge pieces, drilling holes, then adding resin for extra durability, and Voila! Lightweight earrings perfect for dreaming of mermaid days by the sea!
Empty urchins are already hollow on their undersides, making them very easy to display on a wall--simply stick a pushpin into the wall, and hang the urchin on the pushpin!
I have seen other crafters make snowmen and tree ornaments from stacked urchins and I've even seen strands of light up urchins (made with mini lights) which look really neat when the light shines through and highlights the intricate lacy patterns.
Other species of sea urchin look very different from the ones we have in Cape Breton, NS, but they all have that wonderful dotty, symmetrical exterior, making them perfect not only for Arts & Crafts, but also for contemplating the wonders of nature:
just try looking at one. really look.
Now break it apart... see what it did there? Amazing, right?!