Storms are a beachcomber’s dream. They churn the shoreline, shift the sand, and uncover things that haven’t seen daylight in years. After a tropical system moves through, I spend hours - and walk miles - searching for whatever the waves have revealed or carried in from somewhere else. 

 What surprises most people is how many of those finds look like ordinary rocks at first glance. Some of the most fascinating treasures on the beach - from fossilized crabs to floating volcanic stones, even rare whale ambergris - hide in plain sight, disguised as simple stones. 

 That’s why, after a storm, I pick up almost every “rock” I see. More often than you’d think, it turns out not to be a rock at all. 

 Stoned Ghost Crabs 

 One of the rarest beach finds - and one most people walk right past - is a “stoned” or concreted ghost crab. Normally, when a ghost crab dies, its delicate body is quickly scavenged or broken apart by waves and disappears into the sand. 

 But every so often, a crab dies deep inside its burrow, protected from predators and weather. If the conditions are just right, the crab’s body undergoes a natural cementation process that turns it into a crab-shaped stone. 

 Ghost crab burrows can reach three to four feet deep, and when a crab dies intact, its shell, legs, and claws remain attached as the body breaks down. As fatty acids and carbon leach into the surrounding wet sand, calcium carbonate in seawater reacts with the organic material. 

 Over time, this reaction hardens the sediment around the crab, preserving its shape inside a compact, rock-like mass. 

 This process can take months or even several years, and the fossilized crab may stay hidden underground until a storm shifts the sand enough to expose it. That’s why a plain “rock” near the dunes is always worth a second look. If the outline seems oddly symmetrical - or vaguely crab-shaped - you may be holding one of the Gulf’s strangest and most fascinating beach treasures.

 

 Ambergris 

 Ambergris is one of the strangest things that can wash up on a beach, and most people wouldn’t want to touch it if they knew what it was. 

 It comes from sperm whales, formed deep in the whale’s digestive system when indigestible items - usually squid beaks - irritate the intestines. In response, the whale produces a waxy substance that eventually gets expelled into the ocean. 

 Once it’s in the water, ambergris drifts for months or even years. Sunlight, saltwater, and constant motion slowly transform it into a smooth, waxy mass that can look like anything from a small stone to a large boulder. 

 Despite its origin, aged ambergris has a pleasant, musky-sweet scent, which is why high-end perfume makers once prized it before synthetic alternatives became standard. 

 Beachcombers dream of finding ambergris, though the laws surrounding it have changed over time. In Texas, possessing ambergris is illegal because it is considered a byproduct of a protected marine mammal. 

 Although most pieces are small, ambergris can occasionally be found in much larger masses. Some documented finds from other parts of the world have weighed dozens of pounds, though such discoveries are extremely rare and not something Gulf Coast beachcombers should expect. 

 The piece I have was gifted to me from a friend’s family collection. It weighs twenty-three grams, and while I can’t say with absolute certainty that it’s ambergris, it passed the traditional tests beachcombers use: it floats in saltwater, gives off a musky-sweet smell when touched with a hot needle, and has the dense, waxy feel that sets ambergris apart from plastic or synthetic resin. 

 If it is genuine, a piece that size could be worth around eight hundred dollars - though for me, the real value is simply in the mystery and rarity of the find. 

 

 Dominican Amber or Copal 

 Another beach find that can fool even experienced beachcombers is a piece of amber or copal. The one I have has a good chance of being either Dominican amber or copal, which is essentially amber in a younger stage. 

 Copal is less than a million years old, while true amber can date back 15 to 40 million years, formed from the fossilized resin of an extinct legume tree during the Oligocene and Miocene epochs. 

 To most people, amber looks like a chunk of honey-colored plastic, which is probably why it’s often overlooked. Sea-glass hunters tend to spot it more easily because their eyes are trained to look for translucent, colored pieces. 

 Amber can resemble brown bonfire glass, the heat-warped bottle glass left over from old beach bonfires that later tumbles smooth in the surf. The colors and translucence can look similar, but there are ways to tell them apart. 

 When I tested my piece with a hot needle, it released a pine-like scent, which rules out plastic, synthetic resin, or bonfire glass - those give off a harsh, chemical smell when heated. 

 Both amber and copal float in saltwater, and under a black light, one side of my piece fluoresces a soft greenish color. It’s very translucent, and light passes through it easily, which is another sign that it’s natural resin rather than manmade material. 

 One of the things that makes amber especially valuable is when a plant or insect becomes trapped in the resin before it hardens, creating a tiny, transparent snapshot of ancient life.

 

 My piece doesn’t contain any insects or plant material - at least not that I could see under a microscope - but even without inclusions, it’s still a fascinating reminder of how something that looks like a simple beach pebble can turn out to be millions of years old. 

 Pumice Stones - Floating Rocks 

 Pumice stones are one of the most common “not-really-rocks” you’ll find on the beach. They look like ordinary stones, but the moment you pick one up, you can tell the difference. 

 Pumice is incredibly light - so light it floats - because it’s full of tiny air pockets created during volcanic eruptions. 

 Most of the pumice that reaches Texas beaches originates from volcanoes in Mexico and Central America, including the Tuxtla Mountains near Veracruz, Mexico. When underwater eruptions occur, volcanic ash and frothy lava are blasted into the ocean. 

 As the material cools rapidly in seawater, it solidifies into porous, lightweight pumice. Over time, waves carry these pieces northward through the Gulf, rounding them smooth as they tumble toward shore. 

 Pumice can appear in a range of colors - gray, tan, brown, even black - depending on the minerals in the original volcanic material. Because it’s so porous, it’s easy to mistake for a strange piece of coral or a weathered chunk of concrete, but its weight always gives it away. 

 I pick up every pumice stone I find because they’re surprisingly useful. I add them to the bottoms of potted plants and raised beds to help aerate the soil, and I keep one by the outdoor hose to scrub dirt off my hands. 

 If you’ve ever had a pedicure, you’ve probably had a pumice stone used on your feet to smooth calluses - the same kind that washes up on our beaches. 

 Once you start recognizing these oddities, the beach becomes a completely different place. Storms don’t just rearrange the sand - they reveal things that have been hidden for years or carried in from far away. 

 Most people walk right past them, but a curious eye can turn an ordinary beach walk into a treasure hunt. 

 The next time you’re walking the shoreline and an ordinary “rock” catches your eye, pick it up. You never know what story it might tell.