Treasures of the Tide - The Ultimate Sand Dollar Guide

A sand dollar is a flat, burrowing sea urchin belonging to the order Clypeasteroida. Found in shallow ocean waters worldwide, these marine creatures are relatives of sea urchins, starfish, and sea cucumbers. While living sand dollars are covered in tiny purple or brown spines, the white shells we find washed up on beaches are their sun-bleached skeletons — known as “tests.”

When you pick up a sand dollar, you’re holding a natural sculpture of calcium carbonate — nature’s artwork formed by the sea.

Sand dollars come in many varieties depending on where you beachcomb. Common species include the Keyhole Sand Dollar from Florida’s Gulf Coast, the Pacific Sand Dollar from the U.S. West Coast, and the Sea Biscuit, a thicker, puffier relative found in tropical waters.

When beachcombing, it’s important to know whether a sand dollar is still alive before taking it home. Living sand dollars are part of the coastal ecosystem and should be left where they are or gently returned to the water.

If you’re unsure, look for these signs:

• Moving spines: A living sand dollar is covered with thousands of tiny, velvety spines. If you look closely and see those spines moving, the animal is alive.
• Color: Living sand dollars are often darker — purple, brown, gray, or reddish depending on the species — while empty tests found on the beach are usually pale, white, or sun-bleached.
• Texture: A live sand dollar feels velvety because of its covering of fine spines. An empty test feels hard and smooth.
• Movement: Living sand dollars can slowly move using their spines and tube feet.
• Location: Live sand dollars are commonly found partly buried in wet sand or shallow water, while empty tests are more likely to wash ashore.

If it still has moving spines or living tissue, leave it at the shoreline or gently return it to the water.

Once you’ve collected your sun-bleached treasures, a little care will help you bring out their delicate details and preserve them for years to come. Cleaning sand dollars requires patience and a gentle touch — harsh chemicals can cause damage, so natural methods work best.

Step-by-Step Guide

1. Soak in Fresh Water:
Place your sand dollars in a bucket of fresh water for one to two days, changing the water every few hours until it runs clear. This removes sand, salt, and organic material, helping prevent odors or discoloration.

2. Clean Gently:
After soaking, use a soft-bristle toothbrush or small paintbrush to remove any remaining debris. Handle carefully — sand dollars are fragile and can easily break.

3. Use Hydrogen Peroxide Carefully for Whitening:

If an empty sand dollar test still has discoloration after soaking and rinsing, a short soak in standard household hydrogen peroxide can help lighten remaining organic stains. Check it frequently rather than leaving it unattended for a long period, since sand dollar tests are naturally fragile.

Rinse thoroughly afterward and allow it to air-dry completely. Avoid repeated or prolonged chemical soaking, which can make a delicate test more brittle.

Hydrogen Peroxide is gentler than bleach

4. Rinse and Air Dry:
Rinse thoroughly and lay on a towel in a warm, dry area for a full day.

5. Strengthen with a Diluted Glue Solution:
Because sand dollars are so delicate, protect them with a light coat of sealant. Mix equal parts white glue and water, then brush gently across both sides with a soft brush. Once dry, it forms an invisible layer that strengthens the surface while maintaining its natural matte finish.

6. Display or Store:
After they’re dry and sealed, display your sand dollars in jars, frames, or bowls — or pair them with Echoes of the Sea Coastal Glass Prints to bring the serenity of the ocean into your home.

Pro Tip: If your sand dollars still have a yellow tint, repeat the hydrogen peroxide soak once more

These sand dollar facts reveal how extraordinary these ocean treasures truly are:

• Sand dollars are actually flattened relatives of sea urchins — not shells at all.

• The flower-like pattern on top of a sand dollar helps it breathe.

• This familiar flower or star pattern on a sand dollar follows the same five-part symmetry seen in many of its echinoderm relatives.

• The five tiny “doves” inside a broken sand dollar are part of its natural inner structure — delicate pieces that inspired the traditional Legend of the Sand Dollar.

• Sand dollars move using tiny spines on their undersides.

• Living sand dollars can slowly bury themselves beneath the sand, using their tiny spines to move and settle into the seafloor.

• Some sand dollar species can live for around a decade or longer.

• Scientists can estimate a sand dollar’s age by studying the growth rings in its hard outer skeleton — almost like reading the rings of a tree.

• Sand dollars often gather in remarkably dense groups on the seafloor. In some areas, as many as 625 sand dollars can live within a single square yard.

Once your sand dollars are clean and preserved, showcase them beautifully:

• Arrange them in shadow boxes or coastal display frames.

• Add them to a bowl of driftwood and shells for a natural centerpiece.

• Mount them alongside Echoes of the Sea Coastal Glass Prints to create an elegant, seaside wall display.

Your collection tells a story — of shorelines walked, treasures found, and moments of peace by the ocean.